Method and inflatable chamber apparatus for separating layers of tissue

ABSTRACT

An apparatus for tissue dissection and instrument anchoring and methods for using such apparatus are disclosed. The apparatus includes a cannula, a dissection balloon releasably attached to the cannula at the distal end, an anchoring balloon disposed on the cannula, and a means for inflating both balloons.

This application is a continuation of co-pending application Ser. No.10/392,465, filed Mar. 19, 2003, which is a continuation of applicationSer. No. 09/023,134, filed Feb. 12, 1998, now abandoned, which is acontinuation of application Ser. No. 08/583,563, filed Jan. 5, 1996, nowU.S. Pat. No. 5,779,728 which is a continuation-in-part (C.I.P.) of Ser.No. 08/542,666, filed Oct. 13, 1995, now U.S. Pat. No. 5,728,119 ofinventors Jeffrey A. Smith, Daniel T. Wallace, Edwin J. Hlavka, CharlesGresl, John P. Lunsford, and Albert K. Chin, which is a C.I.P. of U.S.application Ser. No. 08/405,284, filed Mar. 16, 1995, now U.S. Pat. No.5,632,761 of inventors Jeffrey A. Smith, Albert K. Chin, and Frederic H.Moll, which is a C.I.P. of Ser. No. 08/365,096, filed Dec. 28, 1994, nowabandoned, of inventors Albert K. Chin and Todd Thompson, which is aC.I.P. of Ser. No. 08/319,552, filed Oct. 7, 1994, now abandoned, ofinventors Albert K. Chin, Jeffrey A. Smith, John P. Lunsford andFrederic H. Moll, which is a C.I.P. of Ser. No. 08/282,287, filed Jul.29, 1994, now U.S. Pat. No. 5,704,372 of inventors Frederic H. Moll,Jeffrey A. Smith, John P. Lunsford and Albert K. Chin, which is a C.I.P.of Ser. No. 07/911,714, filed Jul. 10, 1992, now abandoned, of inventorsAlbert K. Chin and John P. Lunsford, which is a C.I.P. of Ser. No.07/794,590, filed Nov. 19, 1991, now issued as U.S. Pat. No. 5,309,896,of inventors Frederic H. Moll, Charles Gresl, Jr., Albert K. Chin, andPhilip K. Hopper, which is a C.I.P. of Ser. No. 07/706,781, filed May29, 1991, now abandoned, of inventors Frederic H. Moll, Albert K. Chin,Diane E. Caramore, and Frank T. Watkins III. The specifications of theabove-referenced applications, which are commonly owned with presentapplication, are incorporated by reference into the specification of thepresent application.

FIELD OF THE INVENTION

The invention pertains to inflatable tissue separation and retractiondevices and methods of using such devices. The apparatus and methods ofthe invention are useful in any procedure requiring dissection and/orretraction of tissue planes throughout the body including inguinalhernia repair, pelvic lymphadenectomy and bladder neck suspension in thepreperitoneal space; renal, adrenal, aortic and anterior spinal accessin the retroperitoneal space; penile prosthetic reservoir placement inthe anterior abdominal wall; plastic surgery; and augmentationmammaplasty prosthetic placement. By way of example only, use of suchdevices and methods for hernia repair will be described.

BACKGROUND OF THE INVENTION

A hernia is the protrusion of part of a body part or structure through adefect in the wall of a surrounding structure. Most commonly, a herniais the protrusion of part of abdominal contents, including bowel,through a tear or weakness in the abdominal wall, or through theinguinal canal into the scrotum.

An abdominal hernia is repaired by suturing or stapling a mesh patchover the site of the tear or weakness. The mesh patch has a roughsurface that can irritate the bowel and cause adhesions. It is thereforepreferred to install the patch properitoneally (the terms properitonealand preperitoneal are used as synonyms). The mesh patch is preferablyattached to the properitoneal fascia of the abdominal wall and coveredby the peritoneum. To attach the mesh patch to the properitoneal fascia,the peritoneum must be dissected from the properitoneal fascia. This isa difficult process which involves the risk of puncturing theperitoneum. Moreover, strands of properitoneal fat interconnecting theperitoneum and the properitoneal fascia make it difficult to see thesite of the hernia.

The abdominal wall includes various layers of tissue. The peritoneum (P)is the innermost layer. Overlying the peritoneum are several layers oftissue, including the properitoneal fat layer (FL) and the properitonealfascia (F). The properitoneal fascia is the layer to which a mesh patchis preferably attached in hernia repair. The properitoneal fat layerseparates the peritoneum from the properitoneal fascia. Theproperitoneal fat layer is relatively weak, which enables the peritoneumto be separated relatively easily from the fascia.

When the peritoneum is separated from the fascia, separation takes placeat or in the properitoneal fat layer. The properitoneal fat layer canremain attached to the properitoneal fascia, or can come away with theperitoneum. Alternatively, part of the properitoneal fat layer canremain attached to the peritoneum and part of the fat layer can comeaway attached to the peritoneum. Because of the uncertainty in the pointof separation, the layer which is detached will be called theperitoneum, and the layer from which the peritoneum is detached willsometimes be denoted as the overlying layer. Additional layers of tissuelie between the properitoneal fascia and the skin.

An inguinal hernia occurs when the contents of the abdominal cavitybreak through the abdominal wall. As described above, a hernia isrepaired by attaching a piece of mesh to the abdominal wall. To preventthe mesh from causing trauma to the bowel, either through irritation ofthe bowel by the rough surface of the mesh, or by adhesion of the bowelto the mesh, it is preferred to attach the mesh to the properitonealfascia. With the mesh attached to the fascia, the peritoneum covers themesh and isolates the bowel from the mesh.

Conventional techniques of attaching the mesh patch to the properitonealfascia, both laparoscopic and normal, involve blunt dissecting theperitoneum away from the properitoneal fascia, working from inside oroutside the belly. The apparatus and methods according to the inventionenable the peritoneum to be separated from the properitoneal fascia andthe mesh patch attached to the fascia without entering the belly.

Although the following description will describe apparatus and methodsaccording to the invention with respect to hernia repair, the inventiveapparatus and methods are not restricted to hernia repair. The apparatusand methods can also be used in other procedures in which one layer oftissue is separated from another to form a working space between thelayers. These procedures include thoracoscopy in patients with pleuraladhesions; pericardioscopy, or the introduction of an endoscope into thepericardial cavity, in patients with pericardial adhesions;retroperitoneal lymph node dissection, in which the peritoneum on thedistal aspect of the abdominal cavity is separated from the underlyingtissue which includes lymph nodes; and in separating a blood vessel fromsurrounding connective tissue in the course of, for example, afemoropopliteal arterial bypass graft procedure.

Laparoscopic techniques to perform hernia repair are being usedincreasingly frequently. In the conventional procedure for carrying outa hernia repair laparoscopically, an endoscope and instruments areintroduced into the belly through one or more incisions in the abdominalwall, and advanced through the belly to the site of the hernia. Then,working from inside the belly, a long incision is made in the peritoneumcovering the site of the hernia. Part of the peritoneum is dissectedfrom the properitoneal fat layer to provide access to the fat layer.This is conventionally done by blunt dissection, such as by sweeping arigid probe under the peritoneum. In this procedure, it is difficult todissect the peritoneum cleanly since patchy layers of properitoneal fattend to adhere to the peritoneum.

In an alternative known laparoscopic hernia repair procedure, the bellyis insufflated. An incision is made in the abdominal wall close to thesite of the hernia. The incision is made through the abdominal wall asfar as the properitoneal fat layer. The peritoneum is then bluntdissected from the properitoneal fat layer by passing a finger or arigid probe through the incision and sweeping the finger or rigid probeunder the peritoneum. After the peritoneum is dissected from theproperitoneal fat layer, the space between the peritoneum and theproperitoneal fat layer is insufflated to provide a working space inwhich to apply the mesh patch to the properitoneal fascia.

During the blunt dissection process, it is easy to puncture through theperitoneum, which is quite thin. Additionally, after initial dissectionof the properitoneal space, known surgical procedures requireintroduction of various instruments in the space to conduct the surgery.These instruments can cause inadvertent puncture of the peritoneum wallafter the initial dissection. A puncture destroys the ability of thespace between the peritoneum and the fascia to hold insufflation gas;pressurized gas can travel through a puncture in the peritoneum to allowthe fluid to migrate to the abdominal cavity and degrade the pressuredifferential maintaining the properitoneal cavity. Also, it is difficultto dissect the peritoneum cleanly since patchy layers of properitonealfat tend to adhere to the peritoneum. Clearing difficult adhesions cansometimes result in a breach of the peritoneum itself.

U.S. Pat. No. 5,309,896 (of which this application is a C.I.P.),discloses a laparoscopic hernia repair technique that enables a meshpatch to be attached to the properitoneal fascia without breaching theperitoneum. An incision is made through the abdominal wall as far as theproperitoneal fat layer. A multi-chambered inflatable retraction deviceis pushed through the incision into contact with the peritoneum, and isused to separate the peritoneum from the overlying tissue layer. Themain end chamber of the inflatable retraction device is then inflated toelongate the inflatable retraction device towards the site of thehernia. As it inflates, the inflatable retraction device gentlyseparates more of the peritoneum from the overlying tissue layer. Oncethe main chamber of the inflatable retraction device is fully inflated,a second inflatable chamber is inflated. The second inflatable chamberenables the inflatable retraction device to continue to separate theperitoneum from the other tissue layers after the main inflatablechamber has been deflated.

One or more apertures are then cut in the envelope of the maininflatable chamber to provide access to the site of the hernia forinstruments passed into the main chamber. With such an arrangement,instruments pass through the main chamber while the main chamber remainsbetween the peritoneum and the overlying layers. In this way, a patchcan be attached to the properitoneal fascia without breaching theperitoneum.

Until the present invention, it had not been known how to view a spacebetween tissue layers while (or after) dissecting the layers with aballoon, without removing any portion of the dissecting apparatusincluding the balloon, but also without image degradation resulting fromviewing through balloon wall. Nor, until the present invention, had itbeen known to design a balloon (suitable for tissue dissection, tissueretraction, and/or instrument anchoring) to have any of a wide range ofinflated shape and pressure characteristics. For example, it had notbeen known to design a tissue dissection balloon to have inflated shapeand pressure characteristics tailored for producing a working space(between dissected tissue layers) having a particular size and shapeselected from a broad range of sizes and shapes.

SUMMARY OF THE INVENTION

In a class of embodiments, the invention is an apparatus for tissuedissection and instrument anchoring, which includes a dissection balloonhaving a viewing window (preferably a rigid, transparent window) at itsdistal end. The window can but need not be a lens (such as a wide anglelens) having a desired focal length. The window of the dissectionballoon is transparent, and either rigid or non-rigid but sufficientlystrong to retain a desired optical shape while (and after) being pushedagainst tissue layers by a rigid obturator (or other rigid instrument)deployed within the balloon. In preferred embodiments, the window iscup-shaped, in the sense that it has a recessed base for receiving andcapturing the distal end of a rigid obturator or endoscope.

In preferred embodiments, the balloon is a long-necked balloon deployedthrough a cannula. The balloon has an open distal end, and a rigid,transparent window (made of polished, clear polycarbonate or acrylicmaterial or the like) is glued over its open distal end. When the distalend of the balloon has been inserted between tissue layers, an endoscopeextending through the cannula within the balloon can view the tissuelayers through the window (whether or not the balloon is inflated).

In other embodiments, the invention is a dissection balloon having aviewing window at its distal end, for use in an apparatus for tissuedissection, tissue retraction, and instrument anchoring. The window canbut need not be a lens (such as a wide angle lens). In otherembodiments, the invention is a dissection balloon assembly including along-necked dissection balloon having a viewing window at its distalend, and a housing to which the dissection balloon's mouth is attached.The housing is shaped for removable attachment to a tissue retractionand instrument anchoring apparatus including a cannula (with thedissection balloon's neck deployed through the cannula and the windowextending beyond the cannula's distal end).

In other, simplified, embodiments, the invention is a dissectionballoon, useful for separating tissue layers, attached to the distal endof a trocar or obturator. A viewing window which may or may not be alens (such as a wide angle lens) is provided at the distal end of thedissection balloon. A longitudinal bore in the trocar or endoscopeallows inflation fluid and instruments to be introduced into theballoon. The window may be used to view the tissue layers, via anendoscope inserted through the bore and into the balloon, regardless ofwhether the balloon is inflated.

In another class of embodiments, the invention is an apparatus fortissue dissection and instrument anchoring, which includes a dissectionballoon having nonuniform elasticity selected to achieve desiredinflated shape and pressure characteristics. In a preferred embodiment,the dissection balloon comprises a sheet of relatively inelasticmaterial bonded to another sheet of relatively elastic material. Inanother preferred embodiment, the dissection balloon consists of a firstlarge sheet bonded (such as by RF-welding) to a second large sheet, anda reinforcing sheet bonded to the central portion of each large sheet.The two large sheets are made of material having high elasticity(preferably polyurethane), and the reinforcing sheet can be made ofmaterial having high or relatively low elasticity.

In other embodiments, the invention is a balloon (either an anchoring ordissection balloon) having nonuniform elasticity selected to achievedesired inflated shape and pressure characteristics, for use in anapparatus for tissue dissection, tissue retraction, and instrumentanchoring.

Other embodiments of the invention are methods for using an apparatusfor tissue dissection and instrument anchoring, said apparatus includinga long-necked dissection balloon deployed through a cannula. Thedissection balloon has a window at its distal end, or nonuniformelasticity selected to achieve desired inflated shape and pressurecharacteristics, or both such a window and such nonuniform elasticity.The distal end of the dissection balloon is inserted between tissuelayers and inflated to dissect the tissue layers. In some embodiments,after dissection using the dissection balloon, the dissection balloon isdeflated and withdrawn through the cannula before a medical operation isperformed in a working space between the dissected tissue layers. Inother embodiments, after dissection using the dissection balloon, thedissection balloon is deflated but retained in the patient duringperformance of a medical operation. In other embodiments, where thedissection balloon has lobes of other portions shaped so thatinstruments can be positioned between them, the dissection balloonremains inflated in the patient after the tissue layers have beendissected, instruments are then positioned between the dissected tissuelayers without being obstructed by the inflated dissection balloon(e.g., between lobes or other separated portions thereof), and theinstruments are manipulated to perform a medical operation.

Another embodiment of the invention is a technique for packing a balloonin a manner which provides a tunnel through the packaged balloon forinsertion of a laparoscope or other instrument, and which eliminates theneed for packaging the balloon with an obturator positioned within it.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C and 2A-2B show a two-component apparatus for separatingtissue layers and insufflating the space between the separated layers,where:

FIG. 1A is the separation component of the two-component apparatus;

FIG. 1B is part of the distal part of the separation component of thetwo-component apparatus with the main envelope in its everted position;

FIG. 1C is part of the distal part of the separation component of thetwo-component apparatus with the main envelope in its inverted position;

FIG. 2A is the insufflation component of the two-component apparatuswith the toroidal inflatable chamber in its collapsed state; and

FIG. 2B is the insufflation component of the two-component apparatuswith the toroidal inflatable chamber in its expanded state.

FIGS. 3A-3I are longitudinal cross sections of the abdomen illustratinga method of using a two-component apparatus to separate the peritoneumfrom the overlying layer, where:

FIG. 3A shows an incision made through the abdominal wall, including theproperitoneal fat layer, excluding the peritoneum;

FIG. 3B shows the distal part of the separation component of atwo-component apparatus inserted into the incision (the separationcomponent includes the main envelope in its collapsed state);

FIG. 3C shows the main envelope inflated to its expanded state toseparate the peritoneum from the overlying layer;

FIG. 3D shows the main envelope returned to its collapsed state;

FIG. 3E shows the separation component removed from the incision;

FIG. 3F shows the distal part of the insufflation component of thetwo-component apparatus inserted into the incision;

FIG. 3G shows the toroidal inflatable chamber of the insufflationcomponent inflated to its expanded state and the anchor flange slid intocontact with the skin of the abdominal wall to provide a gas-tight seal;

FIG. 3H shows the working space between the peritoneum and the overlyinglayer insufflated with a gas passed through the bore of the insufflationcomponent; and

FIG. 3I shows additional instruments passed through gas-tight trocarsheaths into the insufflated working space to repair the hernia byattaching a mesh patch to the properitoneal fascia.

FIGS. 4A-4C show an embodiment of a first one-component apparatus fortissue dissection and instrument anchoring, where:

FIG. 4A shows a main embodiment of the one-component apparatus with themain envelope in its expanded state;

FIG. 4B shows details of the area marked “A” at the distal end of thetube assembly in FIG. 4A; and

FIG. 4C shows the distal part of the tube assembly with the toroidalinflatable chamber in its expanded state.

FIGS. 5A-5D show an alternative one-component apparatus for tissuedissection and instrument anchoring, where:

FIG. 5A shows the alternative embodiment with the main envelope in itsexpanded state;

FIG. 5B shows the elongated main envelope of the alternativeone-component apparatus;

FIG. 5C shows the distal part of the tube assembly of the alternativeone-component apparatus with the main envelope in its everted state; and

FIG. 5D shows the distal part of the tube assembly of the alternativeone-component apparatus with the main envelope in its inverted state.

FIGS. 6A-6H are longitudinal cross sections of the abdomen illustratinga method of using a one-component apparatus to separate the peritoneumfrom the overlying layer, wherein:

FIG. 6A shows an incision made through the abdominal wall, including theoverlying layer, excluding the peritoneum;

FIG. 6B shows the distal part of the tube assembly of the one-componentapparatus inserted into the incision. The tube assembly includes themain envelope in its collapsed state;

FIG. 6C shows the main envelope inflated to its expanded state toseparate the peritoneum from the overlying layer;

FIG. 6D shows the main envelope returned to its fully collapsed state;

FIG. 6E shows the apparatus advanced into the incision such that theenvelope of the toroidal inflatable chamber clears the incision;

FIG. 6F shows the toroidal inflatable chamber inflated to its expandedstate;

FIG. 6G shows the anchor flange slid into contact with the skin of theabdominal wall. The anchor flange together with the expanded toroidalinflatable chamber provides a gas-tight seal; and

FIG. 6H shows the space between the peritoneum and the overlying layerinsufflated with a gas passed through the bore of the apparatus.

FIGS. 7A and 7B show a second embodiment of a one-component apparatus,wherein:

FIG. 7A shows the second one-component apparatus with the main envelopein its expanded state; and

FIG. 7B shows the second one-component apparatus with the main envelopein its collapsed state.

FIG. 8A shows the second one-component apparatus with the main envelopein its expanded state and an endoscope passed through the bore of theouter tube into the main inflatable chamber.

FIG. 8B shows the second one-component apparatus with the maininflatable chamber in its partially expanded state and an endoscopepassed through the bore of the inner tube and through the bore of themain envelope.

FIGS. 9A-9I show an alternative method of using either a one-componentor two-component apparatus to separate the peritoneum from the overlyinglayer near the groin, with the apparatus inserted through an incisionnear the umbilicus. FIGS. 9A-9H are longitudinal cross sections of theabdomen, wherein:

FIG. 9A shows an incision made through the abdominal wall, including theoverlying layer, excluding the peritoneum;

FIG. 9B shows the distal part of the apparatus inserted into theincision. A tube assembly of the apparatus includes a main envelope inits collapsed state;

FIG. 9C shows the main envelope inflated to a partially-expanded stateto separate part of the peritoneum from the overlying layer;

FIG. 9D shows the main envelope returned to its collapsed state;

FIG. 9E shows the apparatus advanced in the direction of the groin tobring the main envelope to the limit of the separated part of theperitoneum;

FIG. 9F shows the main envelope re-inflated to a partially-expandedstate to separate an additional part of the peritoneum from theoverlying layer;

FIG. 9G shows the main envelope advanced to close to the site of thehernia and re-inflated to its fully inflated state to create a workingspace; and

FIG. 9H shows a component of the apparatus advanced through the tunnelinto the working space, and the toroidal inflatable chamber inflated toform a gas-tight seal with the entrance of the tunnel.

FIG. 9I is a plan view of the abdomen showing a component of theapparatus in position with its distal end in the working space and itstoroidal inflatable chamber forming a gas-tight seal with the entranceof the tunnel. FIG. 9I shows the lesser extent to which the peritoneumis detached in the tunnel compared with in the working space.

FIG. 10 is a perspective view of a preferred embodiment of the inventiveone-component apparatus for tissue dissection, tissue retraction, andinstrument anchoring.

FIG. 11 is an exploded view of obturator 515, retaining ring 514, andthe dissection balloon subassembly of the FIG. 10 apparatus.

FIG. 12 is an exploded cross-sectional view of the dissection balloonsubassembly of the FIG. 10 apparatus.

FIG. 13 is a perspective view of the tissue retraction and instrumentanchoring subassembly of the FIG. 10 apparatus.

FIG. 14 is a partially side elevational, partially side cross-sectionalview of the FIG. 10 apparatus (with balloon 512 inflated and endoscope515′ substituted for obturator 515).

FIG. 15 is a perspective view of an alternative instrument anchoringsubassembly, for use in the FIG. 10 apparatus as a substitute for theFIG. 13 subassembly.

FIG. 16 is a plan view of a dissection balloon designed in accordancewith the invention.

FIG. 17 is a cross-sectional view of the balloon of FIG. 16, taken alongline A-A.

FIG. 18 is a cross-sectional view of the balloon of FIG. 16, taken alongline B-B.

FIG. 18A is an end view of an alternative implementation of thedissection balloon of FIG. 16, when inflated, and with a window attachedat its distal end.

FIG. 18B is a side elevational view of the alternative implementation ofthe dissection balloon of FIG. 16, when inflated, and with a windowattached at its distal end.

FIG. 18C is an end view of a preferred implementation of the dissectionballoon of FIG. 16, when inflated, and with a window attached at itsdistal end.

FIG. 18D is a side elevational view of the preferred implementation ofthe dissection balloon of FIG. 16, when inflated, and with a windowattached at its distal end.

FIG. 19 is a side elevational view of a balloon window for use as window508 of the FIG. 10 apparatus.

FIG. 20 is a side elevational view of another balloon window for use aswindow 508 of the FIG. 10 apparatus.

FIG. 21 is a side elevational view of a third balloon window for use aswindow 508 of the FIG. 10 apparatus.

FIG. 21A is a perspective view of a fourth balloon window for use aswindow 508 of the FIG. 10 apparatus.

FIG. 21B is a side cross-sectional view of the window of FIG. 21A.

FIG. 21C is an embodiment of the inventive dissection balloon whosedistal end portion is tapered to receive and capture an obturator (orendoscope).

FIG. 22 is a plan view of another dissection balloon designed inaccordance with the invention.

FIG. 23 is a plan view of another dissection balloon designed inaccordance with the invention.

FIG. 24 is a plan view of yet another dissection balloon designed inaccordance with the invention.

FIG. 24A is a plan view of three component sheets of yet anotherdissection balloon designed in accordance with the invention

FIG. 25 is a partially side elevational, partially side cross-sectionalview of a portion of an alternative embodiment of the inventiveapparatus for tissue dissection and instrument anchoring.

FIGS. 26-35 show a method of using the inventive apparatus (such as thatof FIGS. 10-14) to separate the peritoneum from the overlying layer nearthe groin, with the apparatus inserted through an incision near theumbilicus. FIGS. 26-35 are longitudinal cross sections of the abdomen,wherein:

FIG. 26 shows an incision made through the abdominal wall;

FIG. 27 shows the distal end of the apparatus inserted into theincision;

FIG. 28 shows dissection balloon 512 inflated to separate part of theperitoneum from the overlying layer;

FIG. 29 shows balloon 512 returned to its collapsed state;

FIG. 30 shows the apparatus advanced in the direction of the groin tobring balloon 512 to the limit of the separated part of the peritoneum;

FIG. 31 shows balloon 512 re-inflated to separate an additional part ofthe peritoneum from the overlying layer;

FIG. 32 shows balloon 512 advanced to a position close to the site of ahernia and re-inflated to create a working space;

FIG. 33 shows the dissection balloon assembly (512 and 513) and ring 514removed from the rest of the apparatus (i.e., the retraction andanchoring subassembly), and anchor balloon 517 inflated;

FIG. 34 shows foam collar 504 advanced into contact with the patient;and

FIG. 35 shows the working space within the patient being insufflated (asa final step prior to performing a repair procedure within the workingspace).

FIG. 36 is a perspective view of a balloon assembly for use inalternative embodiments of the invention.

FIG. 37 is a plan view of the FIG. 36 assembly.

FIG. 38 is a plan view of the FIG. 36 assembly with a portion of theballoon displaced inwardly.

FIG. 39 shows the FIG. 38 assembly with a rolling device grasping an endof the first, inwardly-displaced balloon portion between two rods.

FIG. 40 is an elevational view of the rolling device of FIG. 39.

FIG. 41 shows the FIG. 39 assembly during rolling of the first balloonportion.

FIG. 42 is a cross-sectional view of the FIG. 36 assembly with first andsecond inwardly-displaced portions of the balloon rolled up into firstand second rolls with an obturator positioned therebetween.

FIG. 43 shows the FIG. 42 assembly, deployed between tissue layers andpartially inflated.

FIGS. 44 and 45 are cross-sectional views of the FIG. 36 assembly withthe balloon in different stages of packing in accordance with analternative method.

FIGS. 46 and 47 are cross-sectional views of the FIG. 36 assembly withthe balloon in different stages of packing in accordance with anotheralternative method.

FIG. 48 is a cross-sectional view of a variation on the FIG. 36assembly, with a balloon having accordion-folds.

FIG. 49 is a cross-sectional view of the FIG. 48 assembly with theballoon having accordion-folds and packed in a compact state.

FIG. 50A is an alternative embodiment of a tissue dissection apparatusin which the dissection balloon is mounted to the distal end of atrocar. The dissection balloon is shown in an inflated condition.

FIG. 50B is an alternative embodiment of a tissue dissection apparatusin which the dissection balloon is mounted to the distal end of asemi-rigid obturator. The dissection balloon is shown in an inflatedcondition.

FIG. 50C is an alternative embodiment of a tissue dissection apparatusin which the dissection balloon is mounted to the distal end of a rigidobturator. The dissection balloon is shown in an inflated condition.

FIG. 51A is a top view of a tissue dissection apparatus illustrating analternative embodiment of a technique for packing the balloon accordingto the present invention.

FIG. 51B is a side view of the tissue dissection apparatus of FIG. 51Afurther illustrating the inventive packing technique.

FIG. 51C is a side view of the tissue dissection apparatus of FIG. 51Billustrating the use of an obturator to extend the balloon in the distaldirection.

FIG. 51D is a cross-sectional side view of the proximal portion of thecannula of the tissue dissection apparatus of FIG. 51A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Throughout the disclosure, including in the claims, the term “balloon”is used in a broad sense to denote any inflatable structure, regardlessof the elasticity of the material comprising it. For example, the termballoon is employed to denote both a thin-walled, inflatable structureconsisting of material of low elasticity (which does not stretchsignificantly during inflation), and also a thin-walled, inflatablestructure consisting of highly elastic material such as a sheet ofurethane (which does stretch significantly during inflation). Inpreferred embodiments to be described, the invention employs a balloonhaving nonuniform elasticity (elasticity which varies from one place toanother on the balloon's surface).

Throughout the disclosure, the term “one-component” apparatus denotes,with reference to an apparatus for tissue dissection and instrumentanchoring, an apparatus having a cannula, wherein after the cannula isinserted into a patient, it remains in the patient during tissuedissection using the apparatus and during anchoring of the apparatus inthe patient to enable performance of medical procedures (subsequent todissection) using the apparatus.

Another device for separating tissue layers is disclosed in U.S. patentapplication Ser. No. 07/911,714, of which this application is a C.I.P.The device includes a main envelope that defines a main inflatablechamber. The apparatus also includes an introducing device forintroducing the main envelope in a collapsed state between the firstlayer of tissue and the second layer of tissue. The introducing deviceinflates the main envelope into an expanded state to separate the firstlayer of tissue from the second layer of tissue, and to create a workingspace between the first layer of tissue and the second layer of tissue.Finally, the apparatus includes an insufflating device for introducinginsufflation gas into the working space between the first layer oftissue and the second layer of tissue.

In a method according to U.S. application Ser. No. 07/911,714, a firstlayer of tissue is separated from a second layer of tissue using a mainenvelope (defining a main inflatable chamber) and insufflation gas. Themain envelope is introduced in a collapsed state between the first andsecond layers of tissue, and the main envelope is then inflated into anexpanded state to create a working space between the first and secondlayers of tissue. Finally, insufflation gas is introduced into theworking space between the first and second layers of tissue.

U.S. Ser. No. 07/911,714 discloses a two-component apparatus includingan inflatable main envelope and a device for introducing the mainenvelope (together constituting a first component which separates afirst layer of tissue from a second layer of tissue to create a workingspace) and an insufflation device which insufflates the working space tomaintain separation of the first layer of tissue from the second layer.The insufflation device is tubular, has an anchor flange slidablymounted on it, and has a toroidal inflatable chamber at its distal end.The anchor flange and toroidal inflatable chamber together form agas-tight seal with the second layer of tissue.

In a method disclosed in U.S. Ser. No. 07/911,714 for using thetwo-component apparatus, the introducing device pushes the main envelopein a collapsed state through an incision through the second layer oftissue to place the main envelope between the first and second layers oftissue. The main envelope is then inflated to gently separate the firstand second tissue layers. An endoscope may be passed through the bore ofthe introducing device into the main chamber to observe the extent ofseparation of the layers of tissue. The main envelope is then returnedto a collapsed state, and the main envelope and introducing device areremoved through the incision. Next, the insufflating device is insertedinto the incision so that its distal end projects into the working spacebetween the two layers of tissue, and the toroidal inflatable chamber isinflated. The anchor flange is slid distally along the insufflatingdevice to compress the second layer of tissue between it and theexpanded toroidal inflatable chamber, and thus to form a gas-tight seal.Insufflating gas is then passed through the insufflating device into theworking space to maintain the separation of the first layer of tissuefrom the second. An endoscope may be passed through the bore of theinsufflating device into the working space to observe within the workingspace.

A two-component apparatus (of the type disclosed in referenced U.S. Ser.No. 07/911,714) for separating tissue layers and insufflating the spacebetween the separated layers is shown in FIGS. 1A-1C and 2A-2B. FIG. 1Ashows a partially cut-away view of separation component 1 of theapparatus. In separation component 1, introducer tube 3 is a rigid tubehaving a bore with a circular cross section that can accommodate anendoscope.

The proximal end of introducer tube 3 is fitted with a port 5, in theproximal end 7 of which is mounted a flapper valve 2. Shutter 6 offlapper valve is operated by button 9. Seat 4 of the flapper valveadditionally forms a gas-tight seal with an endoscope or otherinstrument inserted though the flapper valve into the bore of introducertube 3. Port 5 is also fitted with a valve 11 to which a supply of asuitable inflation fluid can be connected.

Main envelope 12 defines a main inflatable chamber 13. Main envelope 12is fitted to distal end 15 of introducer tube 3. Main envelope 12 isshown in a collapsed state in FIGS. 1B and 1C. Dotted line 12X indicatesthe extent of main envelope 12 with chamber 13 in its expanded state. Itshould be noted that although the main envelope 12 is illustrated asgenerally spherical, it can be formed as oblong, “hockey puck” or discshaped, kidney bean shaped or in other shapes as suited for theparticular dissection contemplated.

Main envelope 12 is preferably formed from an elastomeric material, suchas latex, silicone rubber, or polyurethane. The main envelope can alsobe formed from a thin, inelastic material such as Mylar®, polyethylene,nylon, etc. If an inelastic material is used, it should be suitablypackaged to fit inside the bore of introducer tube 3 when in itscollapsed state.

The preferred elastomeric main envelope 12 can be simply attached to thedistal end 15 of the introducer tube 3 by stretching the main envelopeover the distal end of the introducer tube, as shown in FIG. 1B. Themain envelope is then kept in place by friction resulting from thetension caused by stretching. A suitable adhesive, such as an epoxy orcyanoacrylate adhesive, may additionally or alternatively be used. Othermeans of attaching the main envelope to the inside or the outside of theintroducer tube can be used.

After attachment, main envelope 12 is inverted into the bore of theintroducer tube, as shown in FIG. 1C. Inverting the main envelope intothe bore of the introducer tube makes it easier to use the introducertube to pass the main envelope through an incision and place it adjacentto the peritoneum, as will be described.

The first part of a method (described in U.S. Ser. No. 07/911,714) usingseparation component 1 of the two-component apparatus of FIGS. 1A-1C and2A-2B to separate a first layer of tissue from a second layer of tissuewill next be described with reference to FIGS. 3A-3E (the entire method,for repairing a hernia, will be described with reference to FIGS.3A-3I).

FIGS. 3A-3I show a longitudinal cross section of the lower abdomen. Asindicated by FIG. 3A, an incision about 12-15 mm long is made in theabdominal wall (AW), and is carried through the abdominal wall as faras, and including, the properitoneal fat layer (FL). Distal end 15 ofintroducer tube 3 of separation component 1 is then inserted into theincision to bring the distal end into contact with the peritoneum (P).Additional gentle pressure detaches the part of the peritoneum in theimmediate vicinity of the incision from the overlying layer, as shown inFIG. 3B. FIG. 3B shows the peritoneum (P) detached from theproperitoneal fat layer (FL). The deflated main envelope cannot be seenin FIG. 3B because it is inverted within the bore of introducer tube 3.

A source of a suitable inflation fluid (not shown) is connected to valve11. A gas, preferably air, is the preferred inflation fluid, but othergases, such as carbon dioxide, can be used. A liquid, such as salinesolution, can be used, but liquids are less preferable than gasesbecause liquids change the optical properties of any endoscope insertedinto main inflatable chamber 13. The flow of inflation fluid is turnedon, which ejects the main envelope 12 of main inflatable chamber 13 fromthe bore of introducer tube 3.

The inflation fluid progressively expands the main envelope 12, andhence the main inflatable chamber 13 defined by the main envelope, intoan expanded state (as shown in FIG. 3C). The main envelope expandsbetween the peritoneum and the properitoneal fascia, and gently andprogressively detaches an increasing area of the peritoneum from theoverlying layer as it expands. When the main envelope is in its expandedstate, the main inflatable chamber is preferably about 4″-6″ (100-150mm) in diameter.

Early in the process of expanding the main envelope 12, an endoscope Eis inserted into flapper valve 2 in port 5, as shown in FIG. 3C.Endoscope E is passed through the bore of introducer tube 3 into themain inflatable chamber 13. Once partially expanded, main envelope 12 issufficiently transparent for the extent of the detachment of theperitoneum to be observed through the endoscope.

When a sufficient area of the peritoneum has been detached, the supplyof inflation fluid is turned off. The inflation fluid is then ventedfrom the main inflatable chamber, and main envelope 12 returns to itscollapsed state. The peritoneum remains detached from the properitonealfascia, however, as shown in FIG. 3D. Separation component 1, includingthe collapsed main envelope, is then withdrawn from the incision 1 (FIG.3E).

Insufflation component 21 (shown in FIGS. 2A and 2B) of thetwo-component apparatus of FIGS. 1A-1C and 2A-2B will next be described.Insufflation component 21 comprises inner tube 35 and outer tube 37mounted coaxially, with the outer tube covering the inner tube over mostof the length of the inner tube. The inner tube is similar to theintroducer tube 3 (FIG. 1A), and is a rigid tube having a bore with acircular cross section that can accommodate a 10 mm endoscope.

The proximal end of inner tube 35 is fitted with a port 25, the proximalend 27 of which has a flapper valve 32. Shutter 36 of the flapper valveis operated by button 29. Seat 34 of the flapper valve forms a gas-tightseal with an endoscope (not shown) or an obturator (such as obturator33) inserted though the flapper valve into the bore of inner tube 35.Port 25 is also fitted with a first valve 31 to which a supply of asuitable insufflation fluid can be connected.

Distal end 41 of outer tube 37 stops short of distal end 39 of innertube 35. Insufflation component 21 includes a toroidal inflatablechamber 43. Envelope 45 of toroidal chamber 43 is a cylindrical piece ofa thin elastomeric material, such as latex, silicone rubber, orpolyurethane. Envelope 45 is placed over the distal ends of the innertube and the outer tube. Proximal end 47 of envelope 45 is attached todistal end 41 of the outer tube, and distal end 49 of envelope 45 isattached to distal end 39 of the inner tube 35.

The bore of outer tube 37 is spaced from the outer surface of inner tube35. Annular space 51 between the inner tube and the outer tubeinterconnects toroidal chamber 43 and a second valve 53. Second valve 53is connected to a source of a suitable inflation fluid (not shown).Thus, toroidal envelope 45 can be inflated using an inflation fluidpassing into toroidal inflatable chamber 43 (the volume enclosed byenvelope 45) via the second valve 53 and the annular space 51. Toroidalinflatable envelope 45 is shown in its collapsed state in FIG. 2A, andin its expanded state in FIG. 2B.

Anchor flange 55 is slidably mounted on the outer tube 37, and can belocked in a desired position along the length of the outer tube with asimple over-center action locking lever (not shown). As will bedescribed in detail below, the anchor flange and the toroidal inflatablechamber, in its expanded condition, enable the insufflator component 21to form a gas-tight seal to prevent insufflation gas passed through theinsufflator component from escaping.

The use of insufflation component 21 in the second part of the method ofFIGS. 3A-3I using the two-component apparatus of FIGS. 1A-1C and 2A-2Bwill next be described. It is preferred to use separation component 1 inconjunction with the first part of the method (described with referencedto FIGS. 3A-3E) and for dissecting the first and second tissue layers,but the second part of the method (using insufflation component 21) maybe used in following any other dissection operation including manualdissection with an endoscope, graspers, operating scope or any bluntinstrument which may be used to dissect the tissue layers by sweepingthe area between the layers.

With reference to FIG. 3F, obturator 33 of component 21, having blunttip 57, is inserted past flapper valve 32 (shown in FIG. 2B) into thebore of inner tube 35. Tip 57 of obturator 33 projects beyond the distalend of the inner tube to provide insufflation component 21 with a bluntnose. The blunt nose enables the distal end of insufflation component 21to be atraumatically inserted into the properitoneal space throughincision I. The insufflation component is advanced through the incisionuntil the proximal end of the cylindrical envelope 45 is in theproperitoneal space, clear of the incision, as shown in FIG. 3F.

A suitable source (not shown) of an inflation fluid is attached tosecond valve 53. A gas, such as air or carbon dioxide, can be used forthe inflation fluid; alternatively, a liquid, such as saline can beused. Since the volume of inflation fluid required to inflate thetoroidal inflatable chamber is small, about 15 ml in the preferredembodiment, the inflation fluid can be forced into the toroidalinflatable chamber from a large syringe. Inflation fluid is fed intotoroidal inflatable chamber 43 to expand the toroidal inflatable chamberto its expanded condition, as shown in FIG. 3G.

Anchor flange 55 is then advanced in the direction of arrow 59 alongouter tube 37 to bring anchor flange 55 into contact with the skin ofthe abdominal wall (as shown in FIGS. 3G and 3H). Insufflation component21 is then gripped, and the anchor flange is further advanced slightly.This forces the expanded toroidal inflatable chamber 43 into contactwith the overlying layer, and slightly compresses the abdominal wall(including the overlying layer but excluding the peritoneum) between thetoroidal inflatable chamber and the anchor flange. Once adjusted, theanchor flange is locked in position on the outer tube. The expandedtoroidal inflatable chamber is held against the overlying layer, andforms a gas-tight seal between the insufflation component and theabdominal wall (including the overlying layer but excluding theperitoneum). A suitable source (not shown) of an insufflation gas isattached to first valve 31, and insufflation gas is passed through thebore of inner tube 35 into the working space between the peritoneum andthe overlying layer created by separating by the peritoneum from theoverlying layer using the separation component of the apparatus in thefirst part of the method described above. The pressure of theinsufflation gas re-separates the peritoneum from the overlying layer,as shown in FIG. 3H, and provides a working space in which repair of thehernia can be carried out. The obturator is removed from the bore ofinner tube 35. The bore of inner tube 35 can then be used to passinstruments, such as the endoscope, into the working space to performthe repair procedure. Insufflation pressure is maintained by flappervalve 32.

As part of the hernia repair procedure, additional gas-tight trocarsheaths are inserted through the abdominal wall into the working space,as shown in FIG. 3I. An endoscope (not shown) can be passed into theworking space through the bore of inner tube 35, or through one of theadditional trocar sleeves for observation. If the properitoneal fatlayer remains attached to the properitoneal fascia, it is scraped offthe fascia around the site of the hernia so that the patch can beattached directly to the fascia.

A patch, preferably a Dacron® or Teflon® mesh, shown gripped bygrippers, is passed through the sleeve of one trocar into the workingspace. Using the grippers, the patch is manipulated to place it incontact with the properitoneal fascia over the site of the hernia. Thepatch is attached to the properitoneal fascia by staples inserted usinga stapler passed through the trocar sleeve into the working space.Sutures can alternatively be used to attach the patch to theproperitoneal fascia.

After the treatment procedure is completed, first valve 31 is operatedto release the insufflation gas from the working space. Second valve 53is operated to release the inflation fluid from toroidal inflatablechamber 43. Envelope 45 of the toroidal inflatable chamber returns toits collapsed state, flush with the outer surfaces of the inner tube andouter tube 37. Insufflating component 21 is then withdrawn from theincision, and the incision is closed using sutures or clips. Thepressure of the viscera against the peritoneum returns the peritoneuminto contact with the overlying layer. Over time, the peritoneumreattaches to the overlying layer.

Several embodiments of a one-component apparatus are disclosed in U.S.Ser. No. 07/911,714. Each such one-component apparatus includesassemblies for performing multiple functions, including: introducing andinflating a main envelope to dissect tissue layers within a patient;anchoring the apparatus to the patient and insufflating the workingspace; and returning the inflated main envelope to a collapsed state. Insome of these embodiments, the main envelope is deployed through anelongated tube, and the anchoring means includes an anchor flangeslidably mounted on the elongated tube and a toroidal inflatable chamberat the distal end of the elongated tube. The anchor flange and toroidalinflatable chamber can be controlled to form, together, a gas-tight sealwith the second layer of tissue.

One-component apparatus 121 (one of the one-component apparatusembodiments disclosed in U.S. Ser. No. 07/911,714) is shown in FIG. 4A.Apparatus 121 is similar to insufflation device 21 of FIGS. 2A-2B, andcomponents of apparatus 121 corresponding to those of device 21 areidentified by the same reference numbers as in FIGS. 2A-2B with “100”added thereto. Apparatus 121 comprises tube assembly 160, including aninner tube 135 coaxially mounted inside an outer tube 137. Outer tube137 covers inner tube 135 over most of the length of the inner tube. Theinner tube is a rigid tube having a bore with a circular cross sectionthat can accommodate an endoscope (not shown).

The proximal end of the inner tube 135 is fitted with a port 125, theproximal end 127 of which includes a flapper valve 132. The shutter 136of the flapper valve is operated by the button 129. Additionally, theseat 134 of the flapper valve forms a gas-tight seal with an endoscope(not shown), or other instrument, inserted though the flapper valve intothe bore of the inner tube 135. The port 125 is also fitted with a firstvalve 131 to which a supply of a suitable insufflation fluid can beconnected.

Unlike insufflator device 21 of FIGS. 2A and 2B, the distal end of outertube 137 extends as far as the distal end of inner tube 135. Tubes 135and 137 are connected together over a distal portion 167 of theirlengths (see detail in FIG. 4B). Circumferential groove 169 is formed inthe inner wall of distal portion 167. Groove 169 is shown with awedge-shaped cross section, but can have other cross sections, such assquare, or semi-circular. Circumferential groove 169 retains mainenvelope 112, which defines main inflatable chamber 113, in the bore ofinner tube 135.

Envelope 145 of toroidal inflatable chamber 143 covers the distal partof tube assembly 160. Envelope 145 is a cylindrical piece of thinelastomeric material, such a latex, silicone rubber, or polyurethane.The proximal end 147 and the distal end 149 of the envelope are attachedto the outer surface 163 of the tube assembly using a circumferentialline of adhesive applied at each end of the envelope. An epoxy orcyanoacrylate adhesive is preferably used. When chamber 143 is in itscollapsed state, envelope 145 lies almost flush with the outer surfaceof tube assembly 160.

Outer tube 137 is spaced from inner tube 135 over at least part of itscircumference. Space 151 between the inner tube and the outer tube, andradial passage 161 through the wall of the outer tube interconnectchamber 143 and second valve 153. Second valve 153 is connected to asource of suitable inflation fluid (not shown). Chamber 143 is shown inits collapsed state in FIGS. 4A and 4B, and in its expanded state inFIG. 4C.

Anchor flange 155 is slidably mounted on tube assembly 160, and can belocked in a desired position along the length of the tube assembly witha simple over-center action locking lever (not shown). As will bedescribed below, anchor flange 155 and toroidal inflatable chamber 143in its expanded condition form a gas-tight seal to prevent insufflationgas from escaping.

The apparatus of FIGS. 4A-4C also includes main envelope 112 detachablyattached to the bore of inner tube 135. The main envelope defines maininflatable chamber 113. Main envelope 112 is preferably formed of anelastomeric material such as latex, silicone rubber, or polyurethane(but can also be formed from a thin, inelastic material such as Mylar®,polyethylene, nylon, etc.). If an inelastic material is used forenvelope 112, it should be suitably packaged to fit inside the bore ofthe inner tube when in its collapsed state.

Main envelope 112 is formed such that it has a substantially sphericalshape when in its expanded state, and is also formed with a neck 165.Neck 165 has an outside diameter substantially equal to the diameter ofthe bore of inner tube 135. Neck 165 can be rolled outward a number oftimes, as in the neck of a common toy balloon, or the neck can beattached to a suitable O-ring 171 as shown in FIG. 4B. The rolled neck,or the O-ring attached to the neck, engages with the circumferentialgroove 169 in the inner wall in the inner tube to attach main envelope112 to the inner tube. Main envelope 112 is housed in the bore of theinner tube when the main inflatable chamber is in its collapsed state.

Rip cord 173, attached to neck 165 of main envelope 112, runs proximallyup the bore of inner tube 135 and emerges from port 125 through flappervalve 132. The part of the rip cord 173 emerging from the flapper valvecan be gripped and pulled in a proximal direction to release the rolledneck 165 or the O-ring 171 from the circumferential groove 169. Bypulling further on the rip cord, the entire main envelope can be pulledproximally through the bore of the inner tube.

FIG. 5A shows a one-component apparatus (which is a variation on theapparatus of FIGS. 4A-4C) having an elongated main envelope 112A. Asshown in FIG. 5A (and described in referenced U.S. application Ser. No.07/911,714), tube assembly 160A includes inner tube 135A mountedcoaxially inside outer tube 137A, with the proximal and distal ends ofthe tubes interconnected. Space 151A between the inner tube and theouter tube communicates with the toroidal inflatable chamber through aradial passage in the wall of the outer tube. The space between theinner tube and the outer tube also communicates with the toroidalchamber inflation valve 153A. The bore of the inner tube 135Acommunicates with the port 125A, fitted with the insufflation valve 185.The port 125A is also fitted with a flapper valve 132A, including theflapper valve seat 134A, which maintains gas pressure when the apparatusis used for insufflation. Flapper valve seat 134A also provides agas-tight seal around any instrument, such as endoscope E, passedthrough the flapper valve.

Elongated main envelope 112A is shown in FIG. 5B. The main envelope isan elongated cylinder with a closed distal end 177. The main envelope ispreferably formed from an elastomeric material, such as latex, siliconrubber, or polyurethane. Attached to the proximal end of the mainenvelope is a manifold 175 which mates with the proximal face 127A ofthe port 125A. The manifold 175 is fitted with an O-ring seal 187, whichforms a gas-tight seal with any instrument passed through it. Themanifold 175 is also fitted with the main chamber inflation valve 131Ato which a supply (not shown) of a suitable inflation fluid can beattached to inflate the main inflatable chamber 112A.

Elongated main envelope 112A is passed through flapper valve 132A intothe bore of inner tube 135A. The manifold 175 is engaged with theproximal face 127A of the port 125A. When the manifold is engaged, thedistal end 177 of the main envelope projects beyond the distal end ofthe tube assembly 160A, as shown in FIG. 5C. The distal end of the mainenvelope is then inverted into the bore of the inner tube 135A, as shownin FIG. 5D.

An endoscope, or other suitable instrument, is inserted through O-ringseal 187 to seal the manifold before inflation fluid is passed throughmain chamber inflation valve 131A to inflate main inflatable chamber113A.

Alternatively, seal 187 can be replaced by an additional flapper valve(not shown) so that the main inflatable chamber can be inflated withoutthe need to use an instrument to seal the manifold.

When inflation fluid is passed into main inflatable chamber 113A throughvalve 131A, distal end 177 of main envelope 112A is ejected from innertube 135A. The inflation fluid then progressively expands the mainenvelope 112A, and hence main inflatable chamber 113A defined by themain envelope, into an expanded state as shown in FIG. 5A. The part ofthe main envelope inside the inner tube is subject to the same inflationpressure as the distal end 177 of the main envelope, but is constrainedby the inner tube and so does not inflate.

After using main envelope 112A to separate (dissect) the peritoneum froman adjacent tissue layer, as will be described below, the inflationpressure fluid is vented from main inflatable chamber 113A, and mainenvelope 112A returns to its collapsed state. When the main envelope isin its collapsed state, it can move freely in the bore of inner tube135. The main envelope is removed from the inner tube by disengagingmanifold 175 from the proximal face 127A of port 125A, and usingmanifold 175 to pull the main envelope proximally through the bore ofthe inner tube.

Inflation fluid for the toroidal inflatable chamber (envelope 145A ofwhich is shown in FIG. 5A), is passed through toroidal chamber inflationvalve 153A. Insufflation gas is passed through insufflation valve 185.

The toroidal inflatable chamber and anchor flange 155A of the embodimentof FIGS. 5A-5D are the same as in the embodiment of FIGS. 4A-4C, andwill not be described again.

In a method according to U.S. Ser. No. 07/911,714 of using aone-component apparatus to separate a first layer of tissue from asecond layer of tissue, the elongated tube pushes the main envelope in acollapsed state through an incision through the second layer of tissueto place the main envelope between the first layer of tissue and thesecond layer of tissue. The main envelope is then inflated to gentlyseparate the first layer of tissue from the second layer of tissue,thereby creating a working space between the two layers of tissue. Anendoscope may be passed through the bore of the single elongated tubeinto the main chamber to observe the extent of separation of the layersof tissue. The main envelope is then returned to a collapsed state,detached from the elongated tube, and removed from the working spacebetween the layers of tissue through the bore of the elongated tube. Thetoroidal inflatable chamber at the distal end of the elongated tube isthen inflated into an expanded state. The anchor flange is slid distallyalong the elongated tube to compress the second layer of tissue betweenit and the expanded toroidal inflatable chamber to form a gas-tightseal. Insufflating gas is passed through the elongated tube into theworking space to maintain the separation of the first and second tissuelayers. An endoscope may be passed through the bore of the singleelongated tube into the working space to observe within the workingspace.

Such a method (described in U.S. Ser. No. 07/911,714) of using eitherthe apparatus of FIGS. 4A-4C or that of FIGS. 5A-5D to separate a firstlayer of tissue from a second layer of tissue will next be describedwith reference to FIGS. 6A-6H. For specificity, FIGS. 6A-6H will bedescribed with reference to separation of the peritoneum from theproperitoneal fascia in the course of repairing a hernia using theapparatus of FIGS. 4A-4C.

FIGS. 6A-6H show a longitudinal cross section of the lower abdomen.Incision 1 about 12-15 mm long is made in the abdominal wall, andcarried through the abdominal wall as far as, and including theproperitoneal fat layer as shown in FIG. 6A. Distal end 115 of tubeassembly 160 of apparatus 121 is then inserted into the incision tobring the distal end into contact with the peritoneum. Additional gentlepressure detaches the part of the peritoneum in the immediate vicinityof the incision from the overlying layer, as shown in FIG. 6B. FIG. 6Bshows the peritoneum detached from the properitoneal fat layer. The mainenvelope cannot be seen in FIGS. 6A and 6B because it is inverted withinthe bore of the tube assembly.

A source of inflation fluid (not shown) is connected to valve 131. Agas, preferably air, is the preferred inflation fluid, but other gases,such a carbon dioxide can be used. A liquid, such as saline solution canbe used, but liquids are less preferable because they change the opticalproperties of any endoscope inserted into main inflatable chamber 113.The flow of inflation fluid is turned on, which ejects main envelope 112from the bore of tube assembly 160.

The inflation fluid progressively expands main envelope 112, and hencemain inflatable chamber 113 defined by the main envelope, into anexpanded state as shown in FIG. 6C. The main envelope expands betweenthe peritoneum and the properitoneal fat layer, and gently andprogressively detaches an increasing area of the peritoneum from theoverlying layer as it expands. When the main envelope is in its expandedstate, the main inflatable chamber is preferably about 4″-6″ (100-150mm) in diameter.

Early in the process of expanding main envelope 112, an endoscope E isinserted into flapper valve 132 in port 125 as shown in FIG. 6C.Endoscope E is passed through the bore of tube assembly 160 into maininflatable chamber 113. Once the main envelope is partially expanded,the main envelope is sufficiently transparent for the extent of thedetachment of the peritoneum to be observed using the endoscope.

When a sufficient area of the peritoneum is detached, the supply ofinflation fluid is turned off. The inflation fluid is then vented frommain inflatable chamber 113, and the main envelope progressively returnsto its collapsed state. The peritoneum remains detached from theoverlying layer, however, as shown in FIG. 6D. The main envelope is thenremoved from the bore of tube assembly 160. The different methods ofremoving the main envelope from the bore of the tube assembly for thedifferent forms of the one-component apparatus (that of FIGS. 4A-4C andthat of FIGS. 5A-5D) are described above.

After main envelope 112 has been removed from the bore of the tubeassembly, the tube assembly is advanced into the incision in thedirection of arrow 162 until the proximal end of envelope 145 of thetoroidal inflatable chamber is in the properitoneal space, clear of theincision, as shown in FIG. 6E.

A suitable source (not shown) of an inflation fluid is attached to valve153. A gas, such as air or carbon dioxide, can be used for the inflationfluid; alternatively, a liquid, such as saline can be used. Since thevolume of inflation fluid required to inflate the toroidal inflatablechamber is small, about 15 ml in the preferred embodiment, the inflationfluid can be contained in a large syringe. Inflation fluid is fed intotoroidal inflatable chamber 43 to expand the toroidal inflatable chamberto its expanded condition, as shown in FIG. 6F.

Anchor flange 155 is then advanced in the direction of arrow 159 alongtube assembly 160 to bring the anchor flange into contact with the skinS of abdominal wall AW. Tube assembly 160 is then gripped, and theanchor flange is further advanced slightly. This forces the expandedtoroidal inflatable chamber 143 into contact with the overlying layer,and slightly compresses abdominal wall AW, including the overlying layerbut excluding the peritoneum P, between the expanded toroidal inflatablechamber and the anchor flange, as shown in FIG. 6G. Once adjusted, theanchor flange is locked in position on the tube assembly. The expandedtoroidal inflatable chamber is held against the overlying layer andforms a gas-tight seal with the abdominal wall, excluding theperitoneum.

A suitable source (not shown) of insufflation gas is attached to firstvalve 131, and insufflation gas is passed through the bore of inner tube135 into working space WS between the peritoneum P and the overlyinglayer created by separating the peritoneum from the overlying layer. Thepressure of the insufflation gas re-separates the peritoneum from theoverlying layer, as shown in FIG. 6H, and provides a working space inwhich repair of the hernia can be carried out. The bore of tube assembly160 can be used to pass instruments, such as endoscope E, into theworking space to perform the repair procedure. When no instrument isinserted into the bore of the tube assembly, insufflation pressure ismaintained by the flapper valve.

As part of a hernia repair procedure, additional gas-tight trocarsleeves (not shown) are inserted through the abdominal wall into theworking space. The same procedure described above in connection withFIG. 31 is used to attach a mesh patch to the properitoneal fascia overthe site of the hernia. The process can be observed using an endoscopepassed through the bore of tube assembly 160, or through one of theadditional trocar sleeves.

After the treatment procedure is completed, valve 131 is operated torelease the insufflation gas from the working space WS. Valve 153 isoperated to release the inflation fluid from toroidal inflatable chamber143, which releases compression of the abdominal wall AW, excluding theperitoneum. Toroidal inflatable chamber 143 returns to its collapsedstate, with its envelope 145 flush with the outer surface tube assembly160. The tube assembly is then withdrawn from the incision, and theincision is closed using sutures or clips. The pressure of the visceraagainst the peritoneum returns the peritoneum into contact with theoverlying layer. Over time, the peritoneum reattaches to the overlyinglayer.

In a second embodiment of a one-component apparatus according to U.S.Ser. No. 07/911,714, the introducing device is an outer elongated tube,and the insufflating device comprises an inner elongated tube mounted inthe bore of the outer tube. The proximal ends of the tubes are flexiblycoupled together. One end of the main envelope is everted with respectto the other, and is attached to the distal end of the outer elongatedtube. The other end of the main envelope is attached to the distal endof the inner elongated tube. The main inflatable chamber defined by themain envelope is thus substantially toroidal. The outer elongated tubehas an anchor flange slidably mounted on it. The anchor flange and themain inflatable chamber together form a gas-tight seal with the secondlayer of tissue.

Such second embodiment of a one-component apparatus is shown in FIGS.7A-7B and 8A-8B. In this embodiment, a substantially toroidal shape ofthe main chamber avoids the need to detach and remove the main envelopeat the end of the separation process, and the toroidal main chamberprovides both the separating function of the main chamber and thesealing function of the toroidal chamber of the embodiment of FIGS.4A-4C.

The apparatus of FIGS. 7A and 7B comprises tube assembly 260, includingouter tube 237 to which is attached a twin port assembly 225 comprisingfirst port 226 and second port 228. The first port is provided with afirst flapper valve 202, including flapper valve seat 204. The secondport is provided with a second flapper valve 206, including flappervalve seat 208. Each flapper valve seat forms a gas-tight seal with aninstrument passed through it.

Tube assembly 260 also includes inner tube 235. Inner tube 235 isshorter than outer tube 237. The proximal end 210 of the inner tube isflexibly attached to the proximal end 222 of outer tube 237 and to firstport 226. The flexible attachment enables the distal end 214 of theinner tube to move in the direction shown by the arrow 216. The firstport communicates with the bore of inner tube 235, and the second portcommunicates with the bore of outer tube 237.

Insufflation valve 285 communicates with first port 226, and the bore ofinner tube 235. Main chamber inflation valve 231 communicates withsecond port 228, and the bore of outer tube 237.

Main envelope 212 defines the main inflatable chamber 213 and comprisesa cylindrical piece of an elastomeric material such a latex, siliconerubber, or polyurethane. The apparatus is shown with its main envelopein its collapsed state in FIG. 7B, in which the structure of the mainenvelope can also be seen. The main envelope preferably has a diametersmaller than the outside diameter of the inner tube. One end 230 of themain envelope is attached to distal end 214 of inner tube 235 by meansof a suitable adhesive, such as an epoxy or cyanoacrylate adhesive. Theother end 232 of the main envelope is everted (i.e., turned back onitself to bring the inside surface 234 of the main envelope to theoutside) and attached to the distal end 236 of the outer tube using thesame type of adhesive. The main envelope is preferably attached to theouter surfaces of the inner tube and the outer tube.

FIG. 7A shows main envelope 212 in its expanded state. To reach thisstate, a source of inflation gas is connected to valve 231 and the gasflows into the main inflatable chamber through the bore of outer tube237. The pressure acting on surface 238 of the main envelope 212 causesthe main envelope to assume the toroidal shape shown in FIG. 7A todefine toroidal main chamber 213, with surface 234 defining the “hole”or “bore” through the toroidal main envelope. FIGS. 7A and 7B show thecorrespondence between the surfaces 234 and 238 of the main envelopewhen the main envelope is in a collapsed state (FIG. 7B) and in anexpanded state (FIG. 7A).

Anchor flange 255 is slidably mounted on tube assembly 260, and can belocked in a desired position along the length of the tube assembly.Anchor flange 255 is identical or similar to anchor flange 55 (of FIG.2A) and thus will not be described further.

FIG. 8A shows an endoscope E passed through second flapper valve 206,second port 228, and the bore of outer tube 237 into main inflatablechamber 213. The flexible mounting of inner tube 235 in the outer tubeenables the endoscope to displace inner tube 235 in direction of thearrow 216 to gain access to the main inflatable chamber. The endoscopeis inserted through the second port into the main inflatable chamberduring tissue separation using the apparatus to observe the extent ofthe separation.

FIG. 8B shows an endoscope E passed through first flapper valve 202,first port 226, the bore of inner tube 235, and bore 234 of mainenvelope 212. The distal part of the endoscope emerges from the bore ofthe main envelope 212, and can be advanced beyond the main inflatablechamber 213 to observe tissue such as the site of the hernia moreclosely. The endoscope is inserted through the first port, the innertube, and the bore of the main envelope during insufflation using theapparatus. Instruments other than endoscopes can also be passed to thesite of the hernia through the first flapper valve, the first port, theinner tube, and the bore of the main envelope if desired.

As shown in FIG. 8B, main envelope 212 is in a partially collapsed statethat it preferably assumes during the insufflation phase of theprocedure. During this part of the procedure, the partially collapsedmain inflatable chamber and anchor flange 255 together provide agas-tight seal to prevent the leakage of insufflation gas.Alternatively, insufflation can be carried out with the main inflatablechamber in a fully expanded state.

In a method described in U.S. Ser. No. 07/911,714 of using theembodiment of FIGS. 7A, 7B, 8A, and 8B to separate a first layer oftissue from a second layer of tissue, the outer elongated tube pushesthe main envelope in a collapsed state through an incision through thesecond layer of tissue to place the main envelope between the firstlayer of tissue and the second layer of tissue. The main envelope isthen inflated to gently separate the first layer of tissue from thesecond layer of tissue, and to create a working space between the layersof tissue. An endoscope may be passed through the outer elongated tubeinto the main chamber to observe the extent of separation of the layersof tissue. The anchor flange is slid distally along the introducingdevice tube to compress the second layer of tissue between it and themain inflatable chamber, to form a gas-tight seal. Insufflating gas isthen passed through the bore of the inner elongated tube and the bore ofthe main envelope into the working space to maintain the separation ofthe first layer of tissue from the second. An endoscope may be passedthrough the bore of the inner elongated tube and the bore of the mainenvelope into the working space to observe within the working space.

More specifically, in performing this method, an incision about 12-15 mmlong is made in the abdominal wall, and carried through the abdominalwall as far as, and including, the properitoneal fat layer. The distalend of tube assembly 260 is then inserted into the incision into contactwith the peritoneum. Additional gentle pressure detaches the part of theperitoneum in the immediate vicinity of the incision from the overlyinglayer (at this time, main envelope 212 is inverted within the bore ofthe tube assembly). A source of inflation fluid is then connected tovalve 231. A gas, preferably air, is the preferred inflation fluid, butother gases, such a carbon dioxide can be used. A liquid such as salinesolution can be used, but a gas is preferred to a liquid because liquidschange the optical properties of any endoscope inserted into theinflatable chamber. The flow of inflation fluid is turned on, whichejects the main envelope 212 from the bore of tube assembly 260.

The inflation fluid progressively expands main envelope 212, and hencemain inflatable chamber 213 defined by the main envelope, into anexpanded state. The main envelope expands between the peritoneum and theproperitoneal fat layer, and gently and progressively separates anincreasing area of the peritoneum from the overlying layer as itexpands. When the main envelope is in its expanded state, the maininflatable chamber is preferably about 4″-6″ (100-150 mm) in diameter.

Early in the process of expanding main envelope 212, an endoscope isinserted into first flapper valve 202. The endoscope is passed throughthe bore of outer tube 237 into main inflatable chamber 213. Oncepartially expanded, main envelope 212 is sufficiently transparent forthe extent of the separation of the peritoneum to be observed using theendoscope.

When a sufficient area of the peritoneum is separated, the supply ofinflation fluid is turned off and the endoscope is removed from maininflatable chamber 213. Valve 231 is then opened to allow inflationfluid to vent partially from main inflatable chamber 213 (allowing mainenvelope 212 to return at least partially to its collapsed state).Alternatively, main envelope 212 may be kept fully expanded.

Anchor flange 255 is then advanced along tube assembly 260 to bring theanchor flange into contact with the skin of the abdominal wall. Tubeassembly 260 is then gripped, and the anchor flange is further advancedslightly. This forces the main envelope 212 into contact with theoverlying layer, and slightly compresses the abdominal wall, includingthe overlying layer but excluding the peritoneum, between the mainenvelope and the anchor flange. Once adjusted, anchor flange 255 islocked in position on the tube assembly, and main envelope 212 forms agas-tight seal with the abdominal wall and the peritoneum.

A suitable source of insufflation gas is attached to second valve 285,and insufflation gas is passed through the bore of inner tube 235, andbore 234 of main envelope 212, into the working space between theperitoneum and the overlying layer. The pressure of the insufflation gasre-separates the peritoneum from the overlying layer, and provides alarger working space in which repair of the hernia can be carried out.

An instrument such as an endoscope can be passed through second flappervalve 206, the bore of inner tube 235, and bore 234 of main envelope212, into the working space to perform a repair procedure. When noinstrument is so inserted, insufflation pressure is maintained by secondflapper valve 206.

After the treatment procedure is completed, valve 285 is operated torelease the insufflation gas from the working space. Valve 231 isoperated to release the inflation fluid from main inflatable chamber213, which releases compression from the abdominal wall, excluding theperitoneum. Main envelope 212 returns to its collapsed state inside thebore of outer tube 237.

The tube assembly is then withdrawn from the incision, and the incisionis closed using sutures or clips. The pressure of the viscera againstthe peritoneum returns the peritoneum into contact with the overlyinglayer. Over time, the peritoneum reattaches to the overlying layer.

In another method described in U.S. Ser. No. 07/911,714, access isprovided through the abdominal wall from near the umbilicus to repair ahernia. This method will be described with reference to FIGS. 9A-9I.This method is often preferable to the hernia repair methods describedabove in which the incision is placed close to the site of the hernia,since in practice, it is preferred to make the incision at or near theumbilicus because the boundary between the peritoneum and theproperitoneal fat layer can be more directly accessed near theumbilicus. The midline location of the umbilicus is devoid of musclelayers that would otherwise need to be traversed to reach theproperitoneal fat layer.

In the method of FIGS. 9A-9I, the main envelope is partially expanded,collapsed, and advanced toward the site of the hernia. This sequence isrepeated to progressively separate the peritoneum from the overlyinglayer and form the tunnel from the umbilicus to the site of the hernia.Then, at or near the site of the hernia, the main envelope is fullyexpanded to provide the working space at the site of the hernia. Theworking space is then insufflated to maintain the separation of theperitoneum from the overlying layer. The method of FIGS. 9A-9I can bepracticed using any of the two-component or one-component apparatusesdescribed above. For specificity, the method will be described withreference to a two-component apparatus.

An incision about 12-15 mm long is made in the abdominal wall AW, and iscarried through the abdominal wall as far as, and including, theproperitoneal fat layer FL. The incision is made at the umbilicus U, asshown in FIG. 9A.

Distal end 15 of introducer tube 3 of separation component 1 is theninserted into the incision to bring the distal end into contact with theperitoneum P. Additional gentle pressure detaches the part of theperitoneum in the immediate vicinity of the incision from the overlyinglayer, as shown in FIG. 9B. In FIG. 9B, the peritoneum is shown detachedfrom the properitoneal fat layer FL. Main envelope 12 cannot be seen inFIGS. 9A and 9B because it is inverted within the bore of introducertube 3.

A source of a suitable inflation fluid (not shown), as previouslydescribed, is connected to valve 11. The flow of inflation fluid isturned on, which ejects main envelope 12 of main inflatable chamber 13from the bore of introducer tube 3. The inflation fluid progressivelyexpands main envelope 12, and hence main inflatable chamber 13 definedby the main envelope, into a partially-expanded state, as shown in FIG.9C. The main envelope expands between the peritoneum and theproperitoneal fat layer FL, and gently and progressively detaches anincreasing area of the peritoneum P from the overlying layer near theumbilicus as it expands.

An endoscope (not shown) can be inserted into main inflatable chamber 13through flapper valve 2 and the bore of introducer tube 3. The endoscopecan be used to observe the extent of the separation of the peritoneum,as described above.

When main envelope 12 expanded such that the main inflatable chamber 13is about one-fourth of its fully-expanded diameter, i.e., about1.0″-1.5″ (25-37 mm) in diameter, the supply of inflation fluid isturned off. Valve 11 is then operated to vent inflation fluid from themain inflatable chamber 13. The main envelope progressively returns toits collapsed state, as shown in FIG. 9D. The peritoneum portion DP thatwas separated by the main inflatable chamber remains detached from theoverlying layer, as shown. Alternatively, the main envelope can beinflated to a fully-expanded state.

Separation component 1, including the collapsed main envelope 12, isthen manipulated in the direction indicated by arrow 14, and then in thedirection indicated by arrow 16, to advance distal part 15 of introducertube 3 to the limit of the detached part DP of the peritoneum in thedirection of the groin, as shown in FIG. 9E. An endoscope E insertedthrough flapper valve 2 into the bore of introducer tube 3 enables theposition of the distal part 15 relative to the detached part DP of theperitoneum to be observed.

Once distal part 15 of the introducer tube has been positioned, theseparation component 1 is clamped in position, or is gripped, andinflation fluid is once more passed through the valve 11 and the bore ofintroducer tube 3 into main inflatable chamber 13. The main envelope 12expands once more, increasing the extent of the detached part of theperitoneum towards the groin, as shown in FIG. 9F. The increased extentof the detached part of the peritoneum is indicated by line DP′ in FIG.9F. The extent of the detached part of the peritoneum is increased inthe direction from the umbilicus to the groin, but not in the directiontransverse to this direction. Endoscope E is used to observe the extentof the separation.

The process of collapsing the main envelope 12, advancing the distalpart 15 of the introducer tube to the limit of the detached part DP′ ofthe peritoneum in the direction of the groin, holding the introducertube in position, and partially re-inflating main envelope 12, isrepeated until the detached part of the peritoneum includes theperitoneum over the site of the hernia. This process provides a tunnel Tbetween the incision at the umbilicus and the site of the hernia (asshown in FIGS. 9G, 9H, and 9I).

When the main envelope is in the vicinity of the site of the hernia H,main envelope 12 is fully inflated to form a working space WS includingthe site of the hernia. This is shown in FIG. 9G.

The working space at the site of the hernia is then insufflated. Withthe two-component apparatus, inflation fluid is vented from the maininflatable chamber 13 to collapse main envelope 12, and the separationcomponent 1 is withdrawn from tunnel T through incision I. Insufflationcomponent 21 is introduced into the incision, and advanced through thetunnel until envelope 45 of toroidal inflatable chamber 43 lies withinthe working space WS, clear of the tunnel. Toroidal inflatable chamber43 is inflated, the anchor flange is clamped in position, andinsufflation gas is passed into the working space, as shown in FIG. 9H.Toroidal inflatable chamber 43 provides a gas-tight seal with theentrance of the tunnel.

FIG. 9I is a plan view of the abdomen with insufflation component 21 inplace. The anchor flange has been omitted for clarity. Toroidalinflatable chamber 43 provides a gas-tight seal with the entrance oftunnel T. The extent of the separated peritoneum is indicated by dottedline DP. It can be seen that the lateral extent of the separatedperitoneum is considerably greater in working space WS than in tunnel T.

At this stage, if a one-component apparatus had been used (with the maininflatable chamber remaining in the working space), inflation fluidwould be vented from the main inflatable chamber to collapse the mainenvelope, and the main envelope would be withdrawn from the workingspace through the bore of the tube assembly. The tube assembly would bepartially withdrawn until the envelope of a toroidal inflatable chamber43 lies within the working space, clear of the entrance to the tunnel.The toroidal inflatable chamber 43 would then be inflated, the anchorflange clamped in position, and insufflation gas passed into the workingspace, as already described. The toroidal inflatable chamber 43 wouldseal against the entrance from the tunnel into the working space.

Alternatively, if another type of one-component apparatus had been used(with the main inflatable chamber remaining in the working space), themain envelope would preferably be returned to a partially collapsedstate, and the tube assembly partially withdrawn until the maininflatable chamber lies within the working space, adjacent to theentrance of the tunnel. The anchor flange would be clamped in position,and insufflation gas is passed into the working space as alreadydescribed. The partially-collapsed main chamber would seal against theentrance from the tunnel into the working space.

Regardless of the embodiment of the apparatus used to create theinsufflated working space WS shown in FIG. 9I, the hernia is thenrepaired using a procedure such as that described in connection withFIG. 31.

Before either component 1 or component 21 (or a one-component apparatusthat performs the functions of both components 1 and 21) is insertedinto the patient, its inflatable envelopes and chambers are deflated andpacked into a sheath. One method of packing an inflatable chamber in itsdeflated, compact state is to roll the chamber inwardly from opposinglateral sides.

Above-referenced U.S. Ser. No. 08/405,284 discloses a device whichperforms both dissection and retraction of tissue layers while at leasta part of the device remains in the patient throughout the dissectionand retraction procedure, so that the user need not remove one assemblyfrom the patient and then insert a second assembly into the patient(searching for the dissected spatial plane in order to deploy the secondassembly in the proper position) between the dissection and retractionsteps. In a preferred implementation, the distal end of the device ismoved to a position between tissue layers in the patient. A firstballoon is then inflated between the tissue layers to dissect the tissuelayers. A second balloon, which is used to retract the tissue layers, isthen inflated between the tissue layers. The distal end of the devicefor introducing and inflating first balloon remains in the patient untilthe second balloon has been inflated, so that the tissue layers remainat least partially separated at all times after initial introduction ofthe device between such layers. After retracting the tissue layers withthe second balloon, the first balloon is deflated, e.g., by a puncturingstep which creates an opening in the first balloon. Instruments are thenintroduced into a working space through the opening in the firstballoon. The second balloon, which can be positioned in the interior ofthe first balloon, is inflated to seal the working space so thatinsufflating fluid is impeded from escaping.

A preferred embodiment of the inventive one-component apparatus(identified by reference numeral 600) for tissue dissection andinstrument anchoring, and also tissue retraction, will be described withreference to FIGS. 10, 11, 12, 13, and 14.

FIG. 10 is a perspective view of apparatus 600. FIG. 14 is a partiallyside elevational, partially side cross-sectional view of apparatus 600.FIGS. 11, 12, 13, 16, 17, 18, 19, 20, and 21 are views of portions (orsubstitutes for portions) of apparatus 600. FIG. 11 is an exploded viewof obturator 515, retaining ring 514, and the dissection balloonsubassembly of apparatus 600. FIG. 12 is an exploded cross-sectionalview of the dissection balloon subassembly of apparatus 600. Each ofFIGS. 19, 20, and 21 is a side elevational view of a balloon window foruse as window 508 of apparatus 600. FIG. 13 is a perspective view of thetissue retraction and instrument anchoring subassembly of apparatus 600.

The assembly of FIG. 15 is an alternative anchor balloon assembly whichcan be substituted for that of FIG. 13 in apparatus 600 of FIGS. 10, 11,12, and 14.

With reference to FIG. 10, apparatus 600 includes housing 509, cannula505 (connected to housing 509 and extending out from distal face 509A ofhousing 509), retaining ring 514 (around housing 509), clamp 503 (aroundcannula 505), foam collar 504 (around cannula 505, and attached to clamp503 so that clamp 503 and collar 504 can slide together as a unit alongcannula 505 until clamp 503 locked in a fixed position along cannula505), housing 513, dissection balloon 512 having a long neck 512A (shownin FIG. 11) whose free end is attached to housing 513 and which extendsthrough cannula 505, anchor balloon 517 attached to cannula 505 (neardistal end 505A of cannula 505 as shown in FIG. 14), sheath 506 whichencloses balloons 517 and 512, and obturator 515 (extending throughhousing 513, housing 509, and cannula 505 into the interior of balloon512).

Flapper valve 521 is mounted within housing 509, and a biasing spring(not shown) biases valve 521 in a closed position (not shown in FIG. 14)in which valve 521 rests against an elastomeric seal around an end portin the proximal face of housing 509 (the face at the right end ofhousing 509 in FIG. 14) thus sealing the port. When button 520 isdepressed (such as by ring 514 fitted around housing 509), mechanicallinkage 522 (connected between button 520 and valve 521) holds valve 521in the open position shown in FIG. 14, in which obturator 515 (or asimilarly shaped endoscope or other instrument) is free to pass into theport through the proximal face of housing 509, and through the centralchannel extending through housing 509. When button 520 is released (suchas when ring 514 is removed), linkage 522 allows spring-biased valve 521to return to its normally closed position sealing the port in theproximal face of housing 509. The seat of flapper valve 521 (around theend port in the proximal face of housing 509) preferably forms agas-tight seal with obturator 515 (or an endoscope or other instrument)inserted though the end port and into cannula 505.

During use of the apparatus, after balloon 512 has been inflated (withobturator 515 or another instrument inserted through the end port in theproximal face of housing 509 and into cannula 505), balloon 512 can bedeflated as follows. The obturator (or other instrument) is withdrawnthrough the end port in the proximal face of housing 509 while button520 remains depressed (e.g., while ring 514 remains in place over button520), thus allowing the inflating fluid to escape past the open flappervalve 521 out the end port in the proximal face of housing 509. Anyremaining inflating fluid within balloon 512 can be pumped out using adeflation bulb (or other pump) positioned against port 531 (port 531 caninclude a valve, or it can simply be an open port which accepts a handbulb or syringe), or any such remaining inflating fluid can be forcedout by compressing balloon 512.

With housing 513 detached from the proximal face of housing 509, it issometimes useful to mount a converter in the end port in the proximalface of housing 509, to maintain a fluid seal when an instrument isinserted through the converter (and through the end port) into cannula505. By using differently sized and shaped converters, instruments ofdifferent sizes and shapes can be introduced into cannula 505. Whenperforming a procedure in an insufflated working space in the patientusing such an instrument, use of a converter of an appropriate size andshape may be needed to prevent undesired deflation of the working spacedue to undesired leakage of insufflation gas through the end port in theproximal face of housing 509 around the instrument (if the outerdiameter of the instrument is less than the diameter of the end port).

Mouth 512B of dissection balloon 512 is attached (preferably by glue) totube portion 564 of housing 513, as shown in FIGS. 14 and 12. Withreference to FIG. 14, the apparatus is preferably assembled by removablyattaching the distal face of housing 513 (the left face in FIG. 14) tothe proximal face of housing 509 (such as by snap fitting or bayonetfitting means). Elongated neck 512A of balloon 512 is extended throughtube portion 564 of housing 513, through the central channel of housing509, and through cannula 505. Endoscope 515′ is inserted through seal560 of housing 513, and (within balloon 512) through tube portion 564 ofhousing 513, the central channel of housing 509, and cannula 505 untilthe distal end 515A of endoscope 515′ abuts window member 508 at thedistal end of balloon 512 (as shown in FIG. 14).

In a class of preferred embodiments (to be discussed below), balloon 512comprises a first sheet of thin elastomeric material (such aspolyurethane, latex, or silicone rubber) bonded (e.g., RF-welded) to asecond sheet of thin, inelastic (or having relatively low elasticity)material such as polyester, polyethylene, or nylon film. Balloon 512 ispreferably formed to have a wide profile when expanded, in the sensethat its width (dimension W shown in FIG. 11) when expanded is muchgreater than its expanded height (dimension H shown in FIG. 14). Anotherdissection balloon having a different expanded shape can be substitutedfor balloon 512 in alternative embodiments.

Before the apparatus is first used, balloon 512 is packed againstobturator 515 so as to occupy a small volume (as shown in FIG. 10), sothat the packed balloon 512 does not significantly impede insertion ofobturator 515 into the patient. At an appropriate time during use of theapparatus (e.g., before or during inflation of balloon 512), balloon 512is expanded (inflated as shown in FIG. 14) to occupy a larger volume.Obturator 515 is withdrawn and replaced by an endoscope (e.g., endoscope515′ of FIG. 14) for viewing the patient through window 508 of balloon512. Alternatively, before the apparatus is first used, balloon 512 ispacked against an endoscope (e.g., endoscope 515′) so as to occupy asmall volume, so that the packed balloon 512 does not significantlyimpede insertion of the endoscope into the patient, and allowsvisualization of anatomy during insertion of the device.

Anchor balloon 517 is attached to cannula 505, near distal end 505A ofcannula 505 as shown in FIG. 14. Before the apparatus is first used,balloon 512 is packed against cannula 505 (as shown in FIG. 14) so as tooccupy a small volume, so that the packed balloon 517 does notsignificantly impede insertion of cannula 505 into the patient. Beforethe apparatus is first inserted into a patient, both packed balloons 512and 517 are preferably packed into sheath 506 (sheath 506 is shown inFIG. 10, but not in FIG. 14). At an appropriate time during use of theapparatus, balloon 517 is expanded (inflated) to occupy a larger volume(as shown in FIG. 13). Preferably, balloon 517 has a rounded triangularshape when expanded as shown in FIG. 13. In alternative embodiments,another anchor balloon having a different expanded shape (such astoroidal balloon 519 of FIG. 15) can be substituted for balloon 517. Aswill be described below, balloon 517 is used for retracting tissuelayers and for maintaining insufflation fluid in a working space.

When clamp 503 is locked in a position along cannula 505 pressing foamcollar 504 against the patient, foam collar 504 helps to immobilize theentire apparatus (including housing 509 and cannula 505) and collar 504applies a modest compressive force to the tissue between clamp 503 andinflated balloon 517, thereby helping balloon 517 form a seal to limitthe escape of insufflation gas during laparoscopic procedures.

Sheath 506 (shown in FIG. 10) is preferably perforated but may be formedin any other manner permitting easy opening. Inflation of balloon 512tears a perforated sheath 506 along the perforation and releases bothballoon 512 and balloon 517. Alternatively, sheath 506 may include anindependent opening mechanism, such as a removable thread which bindsthe sheath together, and which can be opened by the operator at adesired time.

Inflation port 531 of housing 513 is used for inflating and deflatingballoon 512. Port 531 is opened by inserting an inflation device, suchas bulb 500 of FIG. 10, into it. When opened, port 531 provides a pathfor inflating balloon 512 by pumping gas (or other fluid) through mouth512B of balloon 512 into the interior of balloon 512, and for deflatingballoon 512 by allowing inflation fluid to escape from balloon 512 outthrough port 531. A conventional hand bulb 500 or a syringe can be usedto inject the fluid through port 531 (or through valves 510 and 511 tobe discussed below). Alternatively, port 531 can be a continually openport that accepts a hand bulb or syringe.

Inflation valve 510 of housing 513 is used for inflating and deflatinganchor balloon 517. Valve 510 is opened by inserting an inflationdevice, such as bulb 500 of FIG. 10, into it. When opened, valve 510provides a path for inflating balloon 517 by pumping gas (or otherfluid) through cannula 505 through mouth 517M of balloon 517 into theinterior of balloon 517, and for deflating balloon 517 by allowinginflation fluid to escape out from mouth 517M of balloon 517 and thenout through valve 510.

Insufflation valve 511 is used to supply insufflation gas or liquid intoa working space within the patient. Valve 511 is typically used whenobturator 515 (or endoscope 515′), the dissection balloon assemblycomprising balloon 512 and housing 513, and ring 514 have been removedfrom the remaining portion (the tissue retraction and instrumentanchoring subassembly) of the FIG. 10 apparatus (and valve 521 has beenclosed, and the anchoring assembly comprising collar 504 and clamp 503has been locked to anchor the remaining portion of the apparatus to thepatient). Valve 511 is opened by inserting an inflation device into it.When opened, valve 511 provides a path for insufflation fluid to flowthrough the channel surrounded by cannula 505 into the working space(sealed by expanded balloon 517 and the clamp assembly 503, 504) andprovides a path for allowing insufflation fluid to escape out from theworking space through valve 511.

We next describe a preferred structure of the dissection balloonassembly in more detail with reference to FIG. 12. To assemble thisassembly, mouth 512B of balloon 512 is glued to a cylindrical rim on theleft face of base 562 (as shown in FIG. 12) of housing 513. Tube 564 isglued to a cylindrical rim on the opposite face of base 562, and theneck 512A of balloon 512 is pulled to the right through base 562 andtube 564 into the configuration shown in FIG. 12. Then, cover 566 isglued to base 562 to form housing 513. Thus, when inflation port 531 ofcover 566 is opened, inflation fluid can be pumped through port 531 andthe volume enclosed by housing 513 into mouth 512B of balloon 512. Mainseal 560 is glued around the central orifice through cover 566, toprovide a fluid seal preventing fluid from escaping out through thisorifice when an obturator or other rod-shaped instrument is insertedthrough the orifice into the interior of balloon 512. Typically, theassembled FIG. 10 apparatus is packaged with an obturator such asobturator 515 extending through seal 560 into the interior of balloon512. At various times during use of the apparatus, the obturator isremoved and replaced by an endoscope (e.g., endoscope 515′ of FIG. 14)having the same or similar outer dimensions. Seal 560 is preferably madeof rubber or another elastomer.

Next, with reference to FIGS. 13 and 14, we describe a preferredstructure of the anchoring and tissue retraction assembly includinghousing 509 and balloon 517. In some implementations, a converter door516 (made of rigid plastic) is slidably mounted to the outside ofhousing 509. In the position shown in FIG. 13, door 516 covers a port(not shown) through the side wall of housing 509. Door 516 can be slidproximally (away from balloon 517) to uncover this port. The port isnormally sealed by a closed second flapper valve (similar to valve 521of FIG. 14) within housing 509. In response to depression of button 520,a second mechanical linkage (similar to linkage 522 of FIG. 14) movesthe second flapper valve to open the port, so that (when door 516 isopen) an instrument can be inserted through the opened port into housing509 and then through cannula 505 into the working space within thepatient. In some implementations, door 516, the port (through the sidewall of housing 509) which can be covered by door 516, and theassociated valve means for opening and closing the port, are omitted.

In a preferred implementation of the FIG. 10 apparatus, port 531,housing 513 (including cover 566 and base 562), and housing 509 are madeof hard plastic (such as that known as ABS plastic), obturator 515 andring 514 are made of hard plastic (such as polypropylene or ABSplastic), clamp 503, cannula 505, and dissection balloon window 508(which can be shaped as a lens) are made of polycarbonate, foam collar504 is made of polyurethane foam, sheath 506 is made of polyurethane,valves 510 and 511 are made of stainless steel and plastic, the flappervalve assembly comprising button 520, link 522, valve 521, and the seatagainst which valve 521 rests when closed is made of stainless steel,ABS plastic, and silicone rubber, and the converter door assemblycomprising door 516 is mode of silicone rubber and polyetherimide.

Any of the balloon cannula systems of referenced U.S. Ser. No.08/365,096 can be employed in alternative implementation of the presentinvention, e.g., to provide a supporting portion which extends into theinterior of the dissection balloon to provide support for the dissectionballoon during inflation.

With reference again to FIG. 13, anchor balloon 517 is substantiallybell-shaped, and composed of two sheets (517A and 517B) bonded together(e.g., by RF-welding) at seams 518A, 518B, and 518C. Outer seam 518Adefines the outline of a bell-shape, semi-circular seam 518B reducespressure induced stresses at the periphery of balloon 517 (andeliminates the need to provide baffles), and seam 518C defines acircular throughhole (through which the longitudinal axis of cannula 505extends, and through which an instrument such as an endoscope can beextended). Outer seam 518A has a semi-circular upper portion which issubstantially concentric with a throughhole defined by seam 518C. Sheet517A has a mouth portion 517M (shown in FIG. 14), and balloon 517 isattached at mouth portion 517M to cannula 505, so that balloon 517 canbe inflated and deflated using valve 510. The shape of balloon 517 andthe strength and elasticity of its component sheets (and thus theinflating fluid pressure within it during use) are chosen so thatinflated balloon 517 (positioned between two dissected tissue layers)not only anchors cannula 505 to the patient but also retracts thedissected tissue layers by a desired amount and alternatively-shaped andstructured anchor balloons will be used for alternative uses.Preferably, sheet 517A is an inelastic plastic sheet (e.g., made ofpolyester) which does not stretch significantly during inflation ofballoon 517 (to define the desired inflated structure of the ballooneven with inflating fluid pressure within the balloon that is adequatefor retracting the tissue layers by the desired amount). Alsopreferably, sheet 517B is a highly elastic sheet (e.g., made ofpolyurethane) which does stretch significantly during inflation. Inalternative embodiments (to be described), anchor balloon 517 isreplaced by another balloon having nonuniform elasticity tailored forthe particular intended use in any of the ways discussed below (e.g.,the anchor balloon of the invention can comprise two large sheets ofrelatively low elasticity as does the balloon of FIG. 23, withrelatively elastic insert sheets bonded to the large sheets as in FIG.23).

FIG. 15 is a perspective view of an alternative anchoring subassemblyfor use in the FIG. 10 apparatus as a substitute for the FIG. 13subassembly. The FIG. 15 subassembly differs from that of FIG. 13 onlyin that the former includes toroidal anchor balloon 519 mounted aroundcannula 505 while the latter includes above-described anchor balloon 517mounted around cannula 505. Preferably, anchor balloon 519 of FIG. 15 ismade of a thin, highly elastic material such as polyurethane or siliconcoated latex, and has a mouth portion at which balloon 519 is mounted tocannula 505 (so that balloon 519 can be inflated or deflated using valve510). When inflated, balloon 519 functions to anchor cannula 505 to thepatient, but typically does not retract dissected tissue layers to thedegree that inflated balloon 517 would retract the same layers.

We next describe preferred implementations of dissection balloon 512(and variations thereon) in more detail. FIGS. 16-18 show a firstpreferred embodiment of balloon 512.

In the embodiment of FIGS. 16-18, balloon 512 includes: first and secondsheets 513A and 513B attached together at seam 512C such as by RF (radiofrequency) welding; and neck reinforcing sheet 513C attached to sheet513A (such as by RF welding) at neck 512A of balloon 512. Preferably,sheets 513A and 513B are polyurethane sheets of 0.002 inch thickness(each having high elasticity so that it stretches substantially duringinflation) and sheet 513C is made of material having low elasticity(e.g., polyester film, or a multilayer film commercially available fromRexham comprising polyurethane and polyester layers) so that it does notstretch significantly during inflation. This preferred embodiment (withwindow 508 attached to its distal end), when inflated, has theappearance shown in FIGS. 18C and 18D, where FIG. 18C is an elevationalview of the distal end of the inflated balloon and FIG. 18D is a sideelevational view of the distal end of the inflated balloon.

In an alternative embodiment, reinforcing sheet 513C is omitted, sheet513A is made of thin, highly elastic material such as polyurethane orsilicon coated latex (having high elasticity so that it stretchessubstantially during inflation) and sheet 513B is made of material(e.g., a multilayer film commercially available from Rexham comprisingpolyurethane and polyester layers) having low elasticity so that it doesnot stretch significantly during inflation. This alternative embodiment(with window 508 attached to its distal end), when inflated, has theappearance shown in FIGS. 18A and 18B, where FIG. 18A is an elevationalview of the distal end of the inflated balloon and FIG. 18B is a sideelevational view of the distal end of the inflated balloon. If bothsheets 513A and 513B were inelastic, there would be relatively highlocalized stress (and wrinkles) at seam 512C when balloon 512 wereinflated. By constructing balloon 512 from two sheets 513A and 513Bhaving substantially different elasticities in accordance with theinvention, puckering and wrinkling at seam 512C is reduced when balloon512 is inflated, and the balloon's inflation characteristics can betuned for desired results, including but not limited to increasedlateral dissection, reduced incidence of epigastric (vein) stripping,and preferential, controlled dissection.

With reference to FIG. 16, distal end portion 512E of balloon 512(opposite the neck 512A) is shaped to accept the end of an obturator orendoscope for control and manipulation of the balloon, and to receive awindow 508 having a groove around a generally cylindrical side wall(best shown in FIGS. 10, 11, and 14).

A preferred technique for manufacturing balloon 512 of FIG. 16 is tobond together sheets 513A and 513B with a weld (indicated by the dashedline around the periphery of FIG. 16) of width X around the sheets'peripheries, and then to bond sheets 513A and 513C together with a weldof width X around their peripheries. Then, the weld is trimmed to awidth Y (in FIG. 16), the trimmed weld's outer periphery is the solidline around the periphery of seam 512C. Then, end portion 512E is formedby cutting bonded sheets 513A and 513B along line 512F (shown in FIG.16). The latter cut gives end portion 512E a cylindrical shape to whicha suitable window 508 (made of rigid material) can be glued.

The width W of balloon 512 of FIG. 16 is longer than the length (thedistance from line B-B to line 512F) of balloon 512, in order toincrease the lateral extent of the tissue layers dissected by thisballoon when it is inflated. In a typical implementation of balloon 512of FIG. 16, width W is 6.8 inches, length L of sheet 513C is 5.875inches, width Z of reinforcing sheet 513C is 0.82 inch, width X of theoriginal (untrimmed) weld around the periphery of balloon 512 is 0.125inch, and width Y of the trimmed weld around the periphery of balloon512 is 0.06 inch.

Each of FIGS. 19, 20, and 21 is a side elevational view of a balloonwindow for attachment to the distal end of the inventive dissectionballoon, as window 508 is attached to the distal end of balloon 512 ofapparatus 600 of the embodiment of FIGS. 10-14. The window shown in eachof FIGS. 19-21 is preferably composed of transparent, rigid materialsuch as polished, clear polycarbonate or acrylic material. The window ofeach of FIGS. 19-21 (and window 508 of FIGS. 10 and 14) functionsmechanically to separate tissue layers when pushed against the tissuelayers by a rigid obturator (or a rigid endoscope such as endoscope 515′of FIG. 14 whose distal end 515A is pushed against window 508 as shownin FIG. 14). In alternative embodiments, the window of the inventiveballoon is transparent and either rigid or non-rigid, but sufficientlystrong to retain a desired optical shape while (and after) being pushedagainst tissue layers by a rigid obturator (or other rigid instrument)deployed within the dissection balloon.

The window of each of FIGS. 19-21 has a circular groove 508A around itsgenerally cylindrical side wall, so that end portion 512E of dissectionballoon 512 shown in FIG. 16 (or a corresponding end portion ofalternative embodiment of the inventive dissection balloon) can beconveniently glued to groove 508A. Alternatively, it can be stepped orformed in another fashion with a surface conducive to gluing ormechanical fastening, and can have a hollow base for accepting thedistal end of an endoscope or obturator (as does the window of FIGS. 21Aand 21B to be discussed below).

The window of FIG. 19 is a wide angle lens, and each of its frontsurface 508B and its rear surface 508C (shown in phantom view in FIG.19) has a curvature chosen to achieve desired wide angle lens opticalproperties.

The window of FIG. 20 is a lens (but not a magnifying lens), and each ofits front surface 508D (having greater curvature than surface 508B ofFIG. 19) and its rear surface 508C (shown in phantom view in FIG. 20)has a curvature chosen to achieve the desired lens optical properties.

The window of FIG. 21 is a magnifying lens, having a flat rear surface508E (not a curved rear surface such as curved surface 508C of FIG. 20).Its front surface 508D has a curvature chosen to achieve the desiredlens optical properties.

The window of FIGS. 21A and 21B is a lens, which has a flat rear opticalsurface 508F and a curved front optical surface 508G. Surface 508G has acurvature chosen to achieve the desired lens optical properties. Thewindow of FIGS. 21A and 21B has a cylindrical skirt 508H which extendsin the proximal direction (away from front surface 508G) from theperiphery of surface 508F. Skirt 508H has multiple functions: to providea surface conducive to gluing or mechanical fastening of a dissectionballoon to the window; and (after the balloon has been attached to thewindow) to guide the distal end of an endoscope or obturator within theballoon into engagement with surface 508F and allow for positive controland manipulation of the balloon in response to movement of the endoscopeor obturator (without tearing the balloon).

As an alternative (or in addition) to employing a cup-shaped window(such as the skirted window of FIGS. 21A and 21B), the balloon itself isshaped so that when the window is attached to the balloon's distal end,the balloon defines a channel that guides the distal end of an endoscopeor obturator within the balloon into engagement with the window. Such achannel also allows for positive control and manipulation of the balloonin response to movement of the endoscope or obturator (without tearingthe balloon). An example of a dissection balloon having such a shape isdissection balloon 912 of FIG. 21C, whose distal end portion 912A istapered to define a channel for receiving and capturing an obturator (orendoscope) 515. When obturator (or endoscope) 515 is moved, the force(e.g., frictional force) it exerts on distal end portion 912A allows forpositive control and manipulation of balloon 912 in response to suchmovement.

The dissection balloon of the invention can have the alternative shapeshown in FIG. 22. Dissection balloon 512′ of FIG. 22 is identical todissection balloon 512 of FIG. 16 except in that it has a circularcross-section (having radius R in the plane of FIG. 22 as shown) ratherthan an oblong cross-section (as does balloon 512 in the plane of FIG.16). As shown in FIG. 22, balloon 512′ includes rectangular neckreinforcing sheet 513C′, but some alternative versions of balloon 512′do not include such a neck reinforcing sheet. The same materials can beused to manufacture balloon 512′ (and each variation on balloon 512′) asare used to manufacture each corresponding version of balloon 512. In atypical implementation of balloon 512′ including neck reinforcing sheet513C′ as shown in FIG. 22, radius R is 2.125 inches, width Z of the neckreinforcing sheet is 0.82 inch, and length L of the neck reinforcingsheet is 5.875 inches.

It is within the scope of the invention to employ a dissection balloon(and/or an anchoring balloon) having nonuniform elasticity selected toachieve desired inflated shape and pressure characteristics. Forexample, dissection balloon 512 of FIG. 16 has been described in anembodiment comprising one sheet of relatively inelastic material bondedto another sheet of relatively elastic material (with or without a thirdsheet of material for reinforcing the balloon neck).

Numerous other implementations of dissection balloons (and/or anchoringballoons) having nonuniform elasticity are contemplated. For example,dissection balloon 712 of FIG. 23 has nonuniform elasticity selected toachieve desired inflated shape and pressure. Dissection balloon 712includes a first large sheet 700 bonded (such as by RF-welding aroundthe periphery of FIG. 23) to a second large sheet (identical to sheet700 but not visible in FIG. 23). The two large sheets are made ofmaterial having low elasticity (preferably a multilayerfilm-commercially available from Rexham comprising polyurethane andpolyester layers, but alternatively a film of other material such aspolyester). Two disk-shaped sheets 704 of material having highelasticity (preferably, polyurethane) are bonded to each large sheet.For example, two disk-shaped sheets 704 are bonded (such as byRF-welding) to sheet 700, each at annular weld region 702 as shown inFIG. 23. Each disk-shaped sheet 704 bonded to large sheet 700 isRF-welded to the corresponding disk-shaped sheet (the disk-shaped sheetbelow it, and thus not visible in FIG. 23) at annular weld region 708shown in FIG. 23. Thus, when balloon 712 is inflated, its inelasticlarge sheets do not stretch significantly, but the elastic annularregions surrounding welds 708 do stretch significantly (and thusfunction as elastic baffles). As a result, balloon 712 has a very flatprofile (in the sense that its inflated height in a directionperpendicular to the plane of FIG. 23 is very small relative to itsmaximum dimension in the plane of FIG. 23), it can be inflated to agreater pressure (when compared to a balloon made entirely of theinelastic material), and the stresses at its welds are more evenlydistributed (when compared to a balloon made of two inelastic sheetsbonded together at a single long weld).

As another example, dissection balloon 812 of FIG. 24 has nonuniformelasticity selected to achieve desired inflated shape and pressure.Dissection balloon 812 consists of a first large sheet 722 bonded (suchas by RF-welding around the periphery of FIG. 24) to a second largesheet (identical to sheet 722 but not visible in FIG. 24), and areinforcing sheet bonded to the central portion of each large sheet. Thetwo large sheets are made of material having high elasticity(preferably, polyurethane) having a first thickness. A reinforcing sheet720 (which can be of the same material and can have the same thicknessas sheet 722) is bonded to the central region of each large sheet (onesuch reinforcing sheet 720 is shown in FIG. 24 RF-welded to sheet 722 atweld regions 721). Unreinforced portions of sheet 722 are visible inFIG. 24 at neck portion 812A of balloon 812 and at the lateral endregions of balloon 812. Thus, in the FIG. 24 embodiment, at least partof neck portion 812A and the lateral end regions of balloon 812 havegreater elasticity than the central portion to which sheet 720 isbonded. So, when balloon 812 is inflated, it has an hourglass profile(in the sense that its inflated lateral end portions stretchsubstantially more than its reinforced center portion). This structureis useful for certain tissue dissection applications where it is desiredto increase the lateral extent of the tissue layers dissected.

In a variation on the FIG. 24 embodiment to be described with referenceto FIG. 24A, the dissection balloon also has nonuniform elasticityselected to achieve desired inflated shape and pressure. This dissectionballoon consists of a six sheets (three of which are shown in FIG. 24A,and the other three of which are identical to those shown in FIG. 24A).The six sheets are bonded together (such as by RF-welding). Four of thesheets are lateral end sheets 722′ made of material having highelasticity (preferably, polyurethane). The two other sheets 720′ arecentral sheets made of material having lower elasticity (or lower heatdeflection temperature sensitivity) than sheets 722′. To construct theballoon, two end sheets 722′ are bonded to the lateral edges of eachcentral sheet 720′ to make a composite sheet, one composite sheet isplaced on the other (with the peripheries of the two composite sheetsmatched), and the two composite sheets are then bonded together aroundtheir matched peripheries.

In another variation on the FIG. 24 embodiment, a dissection balloonconsists of two large sheets (having identical shape) bonded together attheir peripheries, but at least one of the sheets (and preferably eachof the sheets) has greater thickness (and hence lower elasticity) at itscentral portion and lesser thickness (and hence greater elasticity) atits lateral end portions. For example, each large sheet is made ofpolyurethane, its central portion has the same size and shape as doessheet 720 of FIG. 24 with 0.004 inch thickness, and its lateral endportions have 0.002 inch thickness.

In other embodiments, the desired nonuniform elasticity of the inventiveballoon (either an anchoring balloon or a dissection balloon) isachieved by any one (or combinations of two or more) of the following:

1. at least one portion of the balloon is a sheet having a firstthickness and at least one other portion is a sheet having a secondthickness different than the first thickness;

2. at least one portion of the balloon is made of multilayer materialcomprising a first number of layers and at least one other portion ismade of multilayer material comprising a second number of layers, wherethe second number is different than the first number (in suchembodiments, all the layers typically have the same thickness, butalternatively some of the layers are thicker than others); and

3. the balloon is made of materials whose elasticity varies withtemperature, and at least two different portions of the balloon are madeof different materials with different heat deflection temperatures sothat these portions have different elasticities (e.g., because theelasticity of each material depends on exposure to heat, and one portionof the balloon stretches more than another portion when both portionsare subjected to the same temperature and pressure).

With reference again to FIGS. 10-14, the apparatus of FIGS. 10 and 14 isdesigned so that insufflation can be performed after obturator 515 (orendoscope 515′), the dissection balloon assembly (comprising balloon 512and housing 513), and ring 514 have been removed from the anchoring andtissue retraction assembly (comprising elements 509, 503, 504, 505, and517), and after valve 521 has been closed, balloon 517 has beeninflated, and collar 504 and clamp 503 have been locked to anchor thetissue retraction assembly to the patient. After removal of obturator515, ring 514, and the dissection balloon assembly, an endoscope (orother instrument) can be inserted through the end port of housing 509(thereby displacing flapper valve 521), and through cannula 505 into theworking space within the patient (in order to view the working space orperform some medical procedure therein). However, alternativeembodiments of the invention enable such a viewing operation (or medicalprocedure) to be performed (unimpeded by the dissection balloon) inother ways.

For example, the FIG. 25 embodiment enables such a viewing operation (ormedical procedure) to be performed in the following manner. The FIG. 25embodiment is intended to replace the dissection balloon assembly ofFIG. 11 (which comprises housing 513 and balloon 512). The FIG. 25apparatus includes control lever 670 having two ports therethrough:cannula access port 672; and dissection balloon access port 674. Controllever 670 is slidably mounted between housing members 666 and 664. Mouth512B of dissection balloon 512 is attached around the circular rim ofport 674, and balloon 512 is pulled through central channel 664A throughmember 664 so that elongated neck 512A of balloon 512 extends throughchannel 664A as shown in FIG. 25. Thus, when lever 670 is moved to itsupper position (shown in FIG. 25), with port 674 aligned with channel664, an endoscope (or obturator) can be inserted through central channel666A of member 666, through port 674, into the interior of balloon 512(such as during a tissue dissection and tunneling operation).

To inflate the dissection balloon with the endoscope or obturator inplace as described, inflation gas is pumped through port 631 (i.e.,through an opened valve, not shown, in port 631) into mouth 512B of theballoon. O-ring seal 675 between lever 670 and member 666, and O-ringseal 676 between lever 670 and member 664, prevent the inflation gasfrom escaping out from between members 664 and 666. O-ring seal 678mounted to lever 670 around port 674 is compressed against theendoscope, thus preventing the inflation gas from escaping out throughchannel 666A around the endoscope. Thus, a tunneling operation can beviewed using the endoscope (with imaging light entering the endoscopethrough a window such as window 508 mounted at the distal end of balloon512).

To implement a viewing operation or medical procedure (in a mannerunimpeded by dissection balloon 512, such as where it is not desired toview through a window mounted at the balloon's distal end), balloon 512is deflated (the inflation gas escapes out through the opened valve inport 631), the endoscope or obturator is removed from within balloon 512and port 674, and lever 670 is then pushed down to align port 672 withaligned channels 664A and 666A. This translation of lever 670 causeslever 670 to move mouth 512B of the balloon downward, so that theportion of balloon neck 512A adjacent to mouth 512B moves againsttapered section 665 of member 664, away from the aligned longitudinalaxes of channels 664A and 666A. In this configuration, an endoscope (orother instrument) can be inserted though central channel 666A of member666, through port 672, and through channel 664 (but not into theinterior of balloon 512) into the working space within the patient (toenable viewing of the working space, or performance of a medicalprocedure therein, in a manner unobstructed by the dissection balloon).

As an alternative to implementing the FIG. 25 embodiment (but with useof a long-necked dissection balloon deployed through a cannula such ascannula 505 of FIG. 10, with a rigid window such as window 508 of FIG.10 attached to the balloon's distal end), it may be desirable to attachthe window to the distal end of the dissection balloon non-permanently,such as by a tether or hinge (e.g., a living hinge), rather thanpermanently (e.g., by glue). Then, at the end of tunneling using theinflated balloon, the balloon is deflated, the obturator or endoscopeemployed for tunneling is removed from within the balloon, thenon-permanently attached window is moved away (e.g., rotated on itshinge, or pushed away but retained on a tether) from the longitudinalaxis of the cannula. Then, a surgical instrument or endoscope can beinserted through the cannula into the working space within the patientin a manner unimpeded by the window but without removing the balloonfrom the cannula. Where the window is tethered, it can be pushed out thedistal end of the cannula after tunneling (so as to dangle on the tetherin the balloon or between the dissected tissue layers), or the tethercan be pulled out through the proximal end of the cannula (to remove thetethered window from the working space within the patient).

Alternative embodiments of the invention employ an alternative means(other than that embodied in the dissection balloon assembly of FIG. 25or that of FIG. 10) for mounting a long-necked dissection balloon sothat the balloon can be deployed through a cannula during dissection,and then positioned (after dissection) so as not to impede or obstructviewing of a working space or performance of a surgical procedure. Forexample, some embodiments employ a mechanism to disconnect the mouth ofthe deflated dissection balloon (after dissection) from a housing towhich the balloon mouth is attached during dissection. With the balloonmouth so disconnected from the housing (but with the deflated balloonremaining in the working space), an endoscope or other instrument isinserted through the housing (without entering the mouth or interior ofthe balloon) and into a working space between the dissected tissuelayers.

In other embodiments, the deflated dissection balloon is pulled out ofthe cannula (through the cannula's proximal end) after dissection. Inone of these embodiments, the mouth of the dissection balloon isattached to a sliding element in a housing and the body of the balloonextends through a cannula attached to the housing. The balloon isintroduced into a patient and inflated to perform tissue dissection.After dissection, the balloon is deflated, inverted, and pulled backthrough the cannula. The sliding element is then slid out of the way(e.g., away from the cannula's central longitudinal axis) and anendoscope or other instrument is inserted through the housing and thecannula (without entering the mouth or interior of the balloon) into aworking space between the dissected tissue layers.

With reference to FIGS. 26-35, we next describe an embodiment of theinventive method for using an apparatus (such as that of FIGS. 10-14)having a long-necked dissection balloon deployed through a cannula andhaving a window at its distal end. For specificity, FIGS. 26-35 aredescribed with reference to the embodiment of FIGS. 10-14 which includesdissection balloon 512, deployed through cannula 505, which has a rigidwindow 508 (which can be a lens) mounted at its distal end, and whichalso has an endoscope 515′ deployed through cannula 505 and balloon 512(with the distal end of the endoscope abutting window 508). For thepurpose of illustration only, the method is described in the context ofseparating the peritoneum from the properitoneal fascia in the course ofrepairing a hernia. Variations on the described embodiment (and in theapparatus employed to perform it) are useful for performing othermedical procedures throughout the body.

As shown in FIG. 26, an incision about 12-15 mm long is made in theabdominal wall AW, and is carried through the abdominal wall as far as,and including, the properitoneal fat layer FL. The incision is made atthe umbilicus U. The distal end of the apparatus (i.e., window 508 andthe distal portion of balloon 512 to which window 508 is attached) islubricated and then inserted into the incision to bring the distal endinto contact with the peritoneum. Additional gentle pressure is exertedon the proximal end of endoscope 515′, which presses window 508 againstthe peritoneum, thereby detaching the part of the peritoneum in theimmediate vicinity of the incision from the overlying layer (as shown inFIG. 27). In subsequent steps, the apparatus is advanced along theposterior surface of the peritoneum (toward the right in FIG. 26) untilthe distal end of the device is located at or near the groin.

Alternatively, in any of the dissection steps of the method, anobturator or other instrument (having substantially the same shape asendoscope 515′) can be substituted for endoscope 515′. Such otherinstrument can be removed and replaced by an endoscope at any time toenable viewing of the space within the dissected tissue using theendoscope.

At any time, including during inflation of dissection balloon 512 andduring advancement of window 508 between layers of tissue in thepatient, the patient can be viewed by light that has propagated throughwindow 508 into endoscope 515′. To inflate balloon 512, a source of asuitable inflation fluid (not shown, but as previously described), isconnected to port 531 which protrudes from dissection balloon housing513, and the flow of inflation fluid is turned to inflate dissectionballoon 512 at least partially (as shown in FIG. 28). Balloon 512expands between the peritoneum P and the properitoneal fat layer FL andprogressively detaches an increasing area of the peritoneum from theoverlying tissue over the entire dissection area. When using thepreferred embodiment of the apparatus in which balloon 512 has an ovalprofile when expanded (in the sense that its expanded width is muchgreater than its expanded height), balloon 512 should be packed and theapparatus deployed so that expanded balloon 512's largestcross-sectional area is parallel to the tissue layers being dissected(the largest cross-sectional area should be oriented in a planeperpendicular to the plane of FIG. 28 to maximize the area of the tissuedissection while minimizing trauma to the patient).

With reference to FIGS. 29-32, balloon 512 may be inflated and deflateda number of times, rather than just once, to dissect progressively thetissue layers. After inflating balloon 512 the first time (therebypartially dissecting the tissue layers), the inflation fluid in balloon512 is vented and balloon 512 returns to its collapsed state, as shownin FIG. 29. The peritoneum DP that was separated by balloon 512 remainsdetached from the overlying layer. The apparatus, including collapseddissection balloon 512, is then manipulated to advance the distal end(window 508) to the limit of detached peritoneum DP in the direction ofthe groin, as shown in FIG. 30. Endoscope 515′ enables the position ofthe distal end relative to the detached part of the peritoneum to beobserved.

Balloon 512 is then inflated again thereby increasing the extent of thedetached part of the peritoneum towards the groin, as shown in FIG. 31.The extent of the detached part of the peritoneum is increased in thedirection from the umbilicus to the groin, but is not significantlyincreased in the direction transverse to this direction. Endoscope 515′is again used to observe the extent of the separation (in the mannerdescribed above).

The “tunneling” process of collapsing dissection balloon 512, advancingthe distal end of the apparatus to the limit of the detached part of theperitoneum in the direction of the groin, holding the distal end inposition, and re-inflating the dissection balloon, is repeated until thedetached part of the peritoneum includes the site of the hernia. Careshould be exercised to avoid dissecting tissue below the pubic bone, andto avoid forcing the dissection balloon downward into the deep pelvis ina manner that would cause trauma to the bladder.

Then, dissection balloon 512 is deflated (by removing endoscope 515′from the proximal end of the apparatus while ring 514 remains in placeto hold the flapper valve within housing 509 open). Then, the dissectionballoon assembly (comprising housing 513 and deflated balloon 512) andring 514 are removed from the retraction and anchoring assembly of theapparatus, leaving the retraction and anchoring assembly shown in FIG.33 (with the flapper valve within housing 509 closed as a result ofremoval of ring 514). Then, a suitable source of inflation fluid isattached to anchor balloon inflation valve 510, and anchor balloon 517is inflated, leaving the retraction and anchoring assembly in theconfiguration shown in FIG. 33. When fully inflated, anchor balloon 517should not be in direct contact with the bladder's surface.

Then clamp 503 is advanced along cannula 505 toward the incision in thepatient (preferably also, housing 509 is pulled back away from theincision in the patient), and clamp 503 is locked in a position alongcannula 505 in which clamp 503 compresses foam collar 504 against thepatient (as shown in FIG. 34). In this configuration, collar 504 helpsto immobilize the anchoring and retraction assembly (including housing509 and cannula 505) to the patient, and collar 504 applies a modestcompressive force to the tissue between clamp 503 and inflated anchoringballoon 517, thereby helping balloon 517 form a seal to limit the escapeof insufflation gas from working space WS within the patient out throughtunnel T (between collar 504 and balloon 517 in the patient) duringsubsequent medical procedures. Inflated anchor balloon 517 itselfpreferably provides a substantially gas-tight seal with the entrance ofthe tunnel T. Of course, in alternative embodiments, anchor balloon 519(described with reference to FIG. 15) is employed rather than anchorballoon 517 shown in various ones of FIGS. 26-35.

With reference to FIG. 35, the working space WS at the site of thehernia is then insufflated if necessary, by providing insufflation fluid(indicated by arrow F in FIG. 35) through valve 511 and cannula 505 intothe working space WS. The hernia is then repaired using a knownprocedure. During such procedure, instruments can be removed from orinserted through the end port in housing 509 and cannula 505 (and/orinstruments can be introduced into the working space through otherincisions in the abdominal wall of the patient). At the end of theprocedure, the extraperitoneal cavity can be quickly deflated bypressing button 511 to open the flapper valve within housing 509.

In other embodiments of the inventive method (also employing along-necked dissection balloon deployed through a cannula), afterdissection using the balloon, the balloon is deflated and retractedbefore a repair operation is performed in a working space between thedissected tissue layers. In alternative embodiments (also employing along-necked dissection balloon deployed through a cannula), afterdissection using the balloon, the balloon is deflated but retained inthe patient during performance of a repair operation. In otherembodiments employing a long-necked dissection balloon deployed througha cannula, where the balloon has lobes or other portions shaped so thatinstruments can be positioned between them, the balloon remains inflatedin the patient after tissue is dissected using the balloon, instrumentsare then positioned between the dissected tissue layers without beingobstructed by the inflated balloon (e.g., between lobes or otherseparated portions of the inflated balloon), and the instruments aremanipulated to perform a repair operation.

FIGS. 36 and 37 show a preferred dissection balloon 901 for use in theFIG. 10 apparatus (for dissecting the preperitoneal space) as asubstitute for balloon 512 of FIG. 10. When inflated, balloon 901 has anoval profile, with an oblong cross-section (as shown in FIG. 37) in theplane containing its longest dimension. It is understood that thepresent invention may be practiced using a dissection balloon of any ofa wide variety of shapes (suitable for deploying the balloon through acannula) and that the shape of balloon 901 in FIG. 37 is merely anexample. For example, balloon 901 may be spherical, flat, kidney-shaped,cylindrical, or may have any other shape suited for the particulardissection and/or retraction contemplated.

Balloon 901 is preferably mounted to housing 513 (of the type describedwith reference to FIGS. 11 and 12) as shown in FIGS. 36 and 37 but mayalternatively be attached to any other housing. Elongated neck 901A ofballoon 901 has a circular cross-section that can accommodate anendoscope.

As shown in FIG. 36, balloon 901 is formed from first sheet 913 andsecond sheet 915 (connected at seam 943) in a manner described abovewith reference to FIGS. 16-18. Balloon 901 is preferably made of thematerials and fabricated in the manner described above in connectionwith FIGS. 16-24, and can be elastic, inelastic, or partially elasticand partially inelastic.

A preferred method of packing balloon 901 will be described withreference to FIGS. 38-42. As shown in FIG. 38, first lateral portion 917of balloon 901 is initially displaced inwardly (i.e., pushed“inside-out” into the interior of the balloon). Although it is preferredto displace first portion 917 in a direction perpendicular to thelongitudinal axis of the balloon's neck 901A, first portion 917 canalternatively be displaced inwardly in any other direction.

Inwardly-displaced portion 917 is then rolled up using a rolling device921 inserted through neck 901A. Referring to FIGS. 39 and 40, rollingdevice 921 includes two rolling rods 923 for grasping firstinwardly-displaced portion 917, when rods 923 are disposed in theinterior of the balloon. Each rod 923 has a diameter of about ⅛ inch androds 923 are separated by a gap of preferably less than 1/16 inch. Thegap size and diameter of the rods 923 may vary, depending on thethickness of the balloon material. Furthermore, the rolling device 921may include any other feature for grasping the inwardly displacedportion, such as a pair of jaws, a clamp or a pair of elasticallydeformable arms. The rolling device has a knurled handle 925 which isgripped to manipulate it.

Rolling device 921 is rotated to roll the portion 917 as shown in FIG.41 into a roll 931 (shown in FIG. 42). After portion 917 has been rolledinto a sufficiently compact roll 931, second lateral portion 927 ofballoon 901 (opposite first portion 917) is displaced inwardly androlled in the same manner as portion 917 to form a roll 929 (shown inFIG. 42). An obturator (or endoscope) 935 is positioned through neck901A of balloon 901 between rolls 929 and 931 to provide structuralsupport for balloon 901 during insertion into the patient. Rolls 929,931 are positioned on opposite sides of obturator (or endoscope) 935with obturator (or endoscope) 935 preferably including concave portions938 for receiving the rolls 929, 931. The two rolls 929, 931 (and theportion of element 935 between them) are then encased within sheath 933,which is similar or identical to sheath 506 described above inconjunction with the apparatus of FIGS. 10-14.

The compact, deflated, sheathed balloon 901 is introduced into thepatient between two tissue layers to be separated and is then inflated.Balloon 901 may be used for dissecting and/or retracting tissue planesthroughout the body. Referring to FIG. 43 which shows balloon 901 duringinflation in the peritoneum, the inwardly-displaced portions evertduring inflation so that differential motion between balloon 901 andadjacent tissue layers 937 is minimized thereby reducing trauma to thetissue layers.

Although it is preferred to roll the first and second inwardly-displacedportions into first and second rolls 929, 931 within the interior ofballoon 901 (after pushing these portions inside-out into the balloon'sinterior), balloon 901 may be packed in any other manner so long as aninwardly-displaced portion is provided which everts during inflation.For example, with reference to FIGS. 44 and 45, inwardly-displacedportions 917, 927 can be displaced to a side opposite the initialdisplacement and then rolled into rolls 929, 931 as previouslydescribed.

First and second inwardly-displaced portions 917, 927 can alternativelybe rolled in a conventional manner from opposing lateral sides afterportion 917, 927 have been displaced inward as shown in FIGS. 46 and 47.In this case, displaced first and second portions 917, 927 divideballoon 901 into an upper part 939 and a lower part 941. The upper part939, first portion 917, and lower part 941 are then rolled up in aconventional manner as shown in FIG. 47. When balloon 901 is rolled inthe manner shown in FIGS. 46-47, the balloon 901 will suffer the problemof relatively high differential motion between balloon 901 and theadjacent tissue layers during initial inflation and deployment, however,during the end of the inflation, the balloon will have relatively lowdifferential motion relative to the tissue layers. This method ofpacking a balloon is useful when problematic internal structures arepositioned laterally outward from the obturator. When the balloon isformed from first and second sheets 913, 915, the upper and lower parts939, 941 are preferably formed by the first and second sheets,respectively. By configuring balloon 901 in this manner, the first andsecond portions include a part of seam 943 between the first and secondsheets 913, 915. When coupling the first and second sheets 913, 915together with an RF weld, seam 943 forms a relatively thin, rigidperiphery which can cut or otherwise traumatize the tissue layers.Referring to FIG. 43, seam 943 everts into a space 945 between thetissue layers along the lateral edges of balloon 901 thereby minimizingcontact between seam 943 and the tissue layers.

A balloon 901′ having a number of inwardly-displaced portions in theform of accordion-folds 947 (when inflated) as shown in FIG. 48 can beemployed in place of balloon 901 of FIGS. 36-37. FIG. 48 also showsobturator (or endoscope) 935 within balloon 901′ (having been insertedthrough neck 902′ of balloon 901′). FIG. 49 shows balloon 901′ of FIG.48 in a compact, deflated state.

Although preferred balloon packing techniques have been described, theinvention can be practiced using other packing techniques orcombinations of features of the described techniques. For example, asmall roll may be formed in the manner shown in the FIGS. 39 and 41followed by the procedure described with reference to FIG. 47.

FIG. 50A shows a simplified version of an apparatus 1000 according tothe present invention. This apparatus 1000 comprises an introducer tubeor trocar 1 which may be similar to the introducer tube 1 described inreferenced application Ser. No. 07/911,714 and described herein withrespect to FIGS. 1A-1B and 2A-2C. Trocar 1 includes a cannula 3 whichhas a rigid tube having a bore with a circular cross section that canaccommodate an endoscope.

The proximal end of trocar 1 is preferably fitted with a port 5, in theproximal end 7 of which is mounted a flapper valve 2. Shutter 6 offlapper valve is operated by button 9. Seat 4 of the flapper valveadditionally forms a gas-tight seal with an endoscope or otherinstrument inserted though the flapper valve into the bore of trocar 1.Port 5 is also fitted with a valve 11 to which a supply of a suitableinflation fluid can be connected. Naturally, trocar 1 may be providedwith various other types of seals and ports without diverging from thescope of the present invention.

Attached to distal end 15 of the cannula 3 is a dissection balloon 1512preferably having the materials, features, and construction ofdissection balloon 512 of FIG. 10 (including any of the implementationsof balloon 512 discussed above, such as those in which balloon 512 hasnonuniform elasticity) but preferably having a shorter neck 1512A thanballoon 512 (see elongate neck 512A of FIG. 11). Balloon 1512 can beattached to the distal end 15 of cannula 3 by stretching neck 1512A overthe distal end of the trocar and held in place by friction resultingfrom the tension caused by stretching. A suitable adhesive, such as anepoxy or cyanoacrylate adhesive, may additionally or alternatively beused. Other means of attaching the balloon to the inside or the outsideof the cannula can be used.

The balloon 1512 is preferably packed inside or around the distal end ofan obturator and covered with a sheath prior to insertion of the balloon1512 into the patient in a manner similar to that described with respectto the embodiment of FIG. 10 (see obturator 515 and sheath 506 describedwith respect to the embodiment of FIG. 10; an obturator may be insertedthrough cannula 3 in a similar manner). Once the trocar is positionedwithin the patient, an inflation medium is supplied to the balloon viathe valve 11 in the trocar 1. An endoscope may be inserted into theballoon before inflation for observation through the lens, or duringand/or after inflation for viewing through the balloon wall, to permitobservation of balloon position and surrounding tissue.

The apparatus 1000 is simpler than the previously described embodimentsin that it may be provided without a subassembly and anchor balloon 517such as those shown in FIG. 13. Moreover, because the balloon 1512A isitself mounted on the trocar 1, rather than on a narrower tube such asthe cannula 505 which during use is normally inserted into and withdrawnfrom the body through a trocar, balloon 1512 can be a larger and bulkierballoon than balloon 512 of FIGS. 10-12 will typically be.

From this example it should be apparent that the balloons describedherein may be delivered to an anatomical site within a patient by avariety of cannulas or other means in addition to those described withrespect to the assembly of FIG. 10 and the trocar 1 of FIG. 50A. Forexample, a balloon of the type described herein may be attached to thedistal end of a semi-rigid obturator (designated 3A in FIG. 50B) forinsertion into a patient's body, or it may be attached to a flexibleobturator (designated 3B in FIG. 50C) and contained within a rigidsheath 3C telescopically received over the flexible obturator 3B andslidably withdrawn from the balloon prior to inflation (FIG. 50C). Aswith the previously described embodiments, an obturator having a cannulato which the balloon 1512 is attached would preferably include a sealedport at its proximal end through which instruments and inflation fluidmay be introduced for passage into the balloon. Moreover, although theballoon 1512 shown in FIGS. 50A-50C is of the type having a lens 1508(which can be identical to above-described lens 508, or any of theabove-described variations on lens 508), it should be appreciated thatthe configuration of FIG. 50A, 50B, or 50C can be used with any type ofballoon, including those of various shapes and sizes, those formed ofvarious materials, and those provided without viewing windows.

An alternative balloon packing technique is illustrated in FIGS.51A-51D. This technique is one which allows the balloon to be packagedin a manner in which the overall length of the package is decreased.Such a technique may be desirable for a number of reasons.

For example, if a procedure is being carried out on a smaller patientusing a dissecting balloon which is packaged in a manner which gives thepackaged balloon substantial length, the distal end of the balloon mayreach its destination within the body before essential features of thedevice (e.g., the anchor balloon 517 of FIG. 10) have passed into thefascia. Utilizing shorter balloons in such instances is not necessarilydesirable because smaller balloons have less dissecting capacity than dolarger balloons and thus may not provide effective dissection.

Packing the balloon to have a shortened packaged length is alsoadvantageous in that it decreases the amount of packaging materialsneeded for the device and it thereby reduces packaging costs.

A new packing method according to the invention is one in which theoverall packaged length of the device is shortened by packaging thedevice without including an obturator within the packaged device.Referring to FIG. 51A, as with several of the embodiments describedabove, dissection balloon 512 is provided attached to a distal portionof a flexible or rigid tube such as the cannula designated 3D (see, forexample, trocar 1 of FIG. 50A, or obturators 3A and 3B of FIGS. 50B and50C, respectively). The cannula 3D may be formed of a single piece ofmolded flexible polymer having a port 11A for delivering inflation fluidto the balloon and further having an integral self-sealing seal 2A. Theseal 2A permits passage of instruments (such as obturator 515B shown inFIG. 51C) into the cannula and seals itself around such instruments toprevent loss of inflation pressure.

Although the balloon 512 shown in the drawings is of the type having alens 508 as described above, it should be appreciated that this packingtechnique may be used for any type of balloon, including those ofvarious shapes and sizes, those formed of various materials, and thoseprovided without viewing windows.

To pack the balloon 512 according to the present embodiment, the balloonis flattened and then folded proximally against the cannula 3D to theorientation shown in FIG. 51A (top view) and 51B (side view), in amanner similar to that in which an umbrella closes around its shaft.Next, the balloon 512 is folded into a sheath such as sheath 506described above with respect to the embodiment of FIG. 10.

This packing technique differs from the techniques previously describedherein in that with those techniques the balloon is folded tightlyagainst an obturator (such as obturator 515 of FIG. 11) inserted throughthe balloon. In such embodiments, if the obturator is removed prior todeployment of the balloon, a “tunnel” remains within the packagedballoon and a laparoscope may subsequently be inserted into the “tunnel”if desired. However, if the apparatus is packaged and shipped withoutthe obturator in place, portions of the balloon will migrate into thetunnel during shipping and will therefore impede insertion of alaparoscope through the balloon prior to inflation.

When the balloon is folded over the flexible or rigid neck or cannula asdescribed above, the neck maintains a tunnel through the folded andcompressed balloon. This facilitates insertion of a laparoscope or otherinstrument (such as an obturator) through the tunnel and into theballoon to provide visualization and/or to provide stiffness whichfacilitates insertion of the balloon into the body cavity.

In the present embodiment, an obturator 515B may, but need not, bepositioned within the cannula 3D during packing. Referring to FIG. 51C,when the apparatus is to be used for large patients an obturator 515Bmay be advanced through the cannula 3D to push the balloon 512 distallyso as to increase the overall length of the apparatus. Doing so helpsthe balloon 512 to reach the desired depth within the patient fordissection.

It is contemplated that numerous modifications of and variations on thedisclosed embodiments can be made without departing from the scope ofthe invention as defined by the following claims.

1. A surgical device comprising: an elongate tubular member having abore, the bore configured for receiving a surgical instrumenttherethrough; a first inflatable member disposed in a distal region ofthe elongate tubular member, the first inflatable member having aninflated state and a deflated state; a collar disposed on the elongatetubular member, the collar being compressible and capable of engagingbody tissue between the collar and the first inflatable member when thefirst inflatable member is in the inflated state; a first port fluidlycoupled to the first inflatable member; and a second port in fluidcommunication with the the bore.
 2. The device of claim 1, wherein theballoon has a toroidal configuration in the inflated state.
 3. Thedevice of claim 1, wherein the first port and the second port arelocated in a proximal region of the device.
 4. The device of claim 1,further including a first housing located at a proximal end of thedevice.
 5. The device of claim 4, wherein the first port and the secondport are disposed on the first housing.
 6. The device of claim 3,wherein the bore of the surgical instrument has an inner diameter ofabout 10 mm.
 7. The device of claim 1 further including an obturatorinsertable through the bore.
 8. The device of claim 1 further includinga second inflatable member disposed at a distal end of a second housing.9. The device of claim 8, wherein the second housing includes a thirdport that is fluidly coupled to an interior of the second inflatablemember.
 10. The device of claim 7, wherein the introduction of aninflation medium into the second port is communicated to the distal endof the device.
 11. The device of claim 9, wherein the introduction of aninflation medium is communicated to the interior of the secondinflatable member through the third port and causes the secondinflatable member to transition from an uninflated state towards aninflated state.
 12. The device of claim 8, wherein the second housing isreleasably attached to a first housing, the first housing located at aproximal end of the device.
 13. The device of claim 8 further includinga first housing located at a proximal end of the device and the secondhousing being releasably attached to the first housing.
 14. The deviceof claim 13 further including an obturator that is releasably attachedto the second housing.
 15. The device of claim 14, wherein a distalportion of the obturator extends into the interior of the secondinflatable member.
 16. The device of claim 1, further including a valvedisposed in the bore.
 17. The device of claim 1, wherein the collarincludes a locking mechanism for securing a position of the collarrelative to the elongate tubular member.
 18. The device of claim 1,wherein the collar is formed from a foam material.
 19. The device ofclaim 1, wherein the collar has a substantially planar distal faceadapted for contacting tissue.
 20. The device of claim 1, wherein thecollar is slidable with respect to the elongate tubular member.
 21. Thedevice of claim 1, wherein a distal face of the collar conforms to asurface of body tissue located between the first inflatable member andthe collar.
 22. A method of accessing a space comprising the steps of:making an incision through body tissue; inserting a device through theincision, the device including: an elongate tubular member having abore, the bore configured for receiving a surgical instrumenttherethrough, a first inflatable member disposed in a distal region ofthe elongate tubular member, the first inflatable member having aninflated state and a deflated state, a collar disposed on the elongatetubular member, the collar being compressible and capable of engagingbody tissue between the collar and the first inflatable member when thefirst inflatable member is in the inflated state, a first port fluidlycoupled to the first inflatable member, and a second port in fluidcommunication with the bore; and introducing an inflation medium to thefirst port such that the first inflatable member transitions from anuninflated state to an inflated state.
 23. The method of claim 22,wherein the device further includes a valve disposed in the bore. 24.The method of claim 22, further comprising the step of: inserting asurgical instrument through the bore of the device.
 25. The method ofclaim 24, further comprising the step of: performing a procedure usingthe surgical instrument.
 26. The method of claim 22, further comprisingthe step of: insufflating the space by introducing an inflation mediumthrough the bore of the device.
 27. The method of claim 22, wherein thecollar of the device is formed from a foam material.
 28. The method ofclaim 22, wherein the collar has a substantially planar distal faceadapted for contacting tissue.
 29. The method of claim 22, wherein thecollar is slidable with respect to the elongate tubular member.
 30. Themethod of claim 22, wherein a distal face of the collar conforms to asurface of body tissue located between the first inflatable member andthe collar.
 31. The method of claim 29, further comprising the step of:sliding the collar distally towards the first inflatable member suchthat at least a portion of the collar contacts skin of the patient.